PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 28542511-5 2017 We prospectively evaluated the association of urinary biomarkers of nicotine uptake (total nicotine equivalents [TNE]) and CYP2A6 activity (ratio of urinary total trans-3"-hydroxycotinine to cotinine) with lung cancer risk among 2,309 Multiethnic Cohort Study participants who were current smokers at time of urine collection; 92 cases were diagnosed during a mean follow-up of 9.5 years. Cotinine 179-187 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 123-129 30611298-4 2019 As cotinine levels are influenced not only by nicotine intake but also by CYP2A6-mediated nicotine metabolism rate, we performed secondary analyses adjusting for genetic risk score of nicotine metabolism rate and identified five additional novel associations. Cotinine 3-11 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 74-80 29158210-7 2018 The CYP2A6 phenotype ratio (total 3"-hydroxycotinine/cotinine) was significantly higher at early and late pregnancy compared with postpartum (all P < 0.05) and correlated with nicotine C-oxidation (all P < 0.001), suggesting CYP2A6 activity is induced during pregnancy. Cotinine 44-52 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 4-10 27815364-5 2017 CYP2A6 enzyme activity was determined through measurement of cotinine formation from nicotine and 7-hydroxycoumarin formation from coumarin. Cotinine 61-69 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 27488534-2 2016 We conducted a genome-wide association study (GWAS) of CYP2A6 activity, as measured by the urinary ratio of trans-3"-hydroxycotinine and its glucuronide conjugate over cotinine (total 3HCOT/COT), among 2,239 smokers in the Multiethnic Cohort (MEC) study. Cotinine 124-132 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 55-61 26014804-1 2015 BACKGROUND: The highly genetically variable enzyme CYP2A6 metabolizes nicotine to cotinine (COT) and COT to trans-3"-hydroxycotinine (3HC). Cotinine 82-90 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 51-57 26818358-2 2016 However, no study has evaluated the relationship between CYP2A6 genetic variants and the CYP2A6 activity ratio (total 3-hydroxycotinine/cotinine) and their influence on smoking intensity [total nicotine equivalents (TNE)], across five racial/ethnic groups found to have disparate rates of lung cancer. Cotinine 127-135 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 89-95 26014804-1 2015 BACKGROUND: The highly genetically variable enzyme CYP2A6 metabolizes nicotine to cotinine (COT) and COT to trans-3"-hydroxycotinine (3HC). Cotinine 92-95 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 51-57 23936477-1 2013 BACKGROUND: CYP2A6 metabolizes nicotine to its primary metabolite cotinine and also mediates the metabolism of cotinine to trans-3"-hydroxycotinine (3HC). Cotinine 66-74 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 12-18 24859605-1 2014 Metabolism of nicotine to inactive cotinine by hepatic enzyme CYP2A6 is the principal pathway by which active nicotine is removed from circulation. Cotinine 35-43 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 62-68 26132489-1 2015 The Nicotine Metabolite Ratio (NMR, ratio of trans-3"-hydroxycotinine and cotinine), has previously been associated with CYP2A6 activity, response to smoking cessation treatments, and cigarette consumption. Cotinine 61-69 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 121-127 25220663-7 2014 A significant amount of the conversion of nicotine to cotinine was observed in EESC pretreatment by CYP2A6 induction in HepG2 cells. Cotinine 54-62 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 100-106 24163286-0 2014 Influence of CYP2A6*4 genotypes on maternal serum cotinine among Chinese nonsmoking pregnant women. Cotinine 50-58 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 13-19 24163286-2 2014 This study investigated the influence of CYP2A6*4 genotypes on serum cotinine among nonsmoking pregnant women. Cotinine 69-77 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 41-47 24163286-7 2014 RESULTS: Among women who self-reported non-SHS exposure (n = 317), the median serum cotinine levels were 2.83ng/ml for those with CYP2A6*1/*1 genotype, 1.39ng/ml for CYP2A6*1/*4, and 0.77ng/ml for CYP2A6*4/*4, respectively. Cotinine 84-92 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 130-136 24163286-7 2014 RESULTS: Among women who self-reported non-SHS exposure (n = 317), the median serum cotinine levels were 2.83ng/ml for those with CYP2A6*1/*1 genotype, 1.39ng/ml for CYP2A6*1/*4, and 0.77ng/ml for CYP2A6*4/*4, respectively. Cotinine 84-92 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 166-172 24163286-7 2014 RESULTS: Among women who self-reported non-SHS exposure (n = 317), the median serum cotinine levels were 2.83ng/ml for those with CYP2A6*1/*1 genotype, 1.39ng/ml for CYP2A6*1/*4, and 0.77ng/ml for CYP2A6*4/*4, respectively. Cotinine 84-92 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 166-172 24163286-8 2014 Among women who self-reported SHS exposure (n = 228), the median cotinine levels were 3.32ng/ml for those with CYP2A6*1/*1 genotype, 2.38ng/ml for CYP2A6*1/*4, and 1.56ng/ml for CYP2A6*4/*4, respectively. Cotinine 65-73 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 111-117 24163286-8 2014 Among women who self-reported SHS exposure (n = 228), the median cotinine levels were 3.32ng/ml for those with CYP2A6*1/*1 genotype, 2.38ng/ml for CYP2A6*1/*4, and 1.56ng/ml for CYP2A6*4/*4, respectively. Cotinine 65-73 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 147-153 24163286-8 2014 Among women who self-reported SHS exposure (n = 228), the median cotinine levels were 3.32ng/ml for those with CYP2A6*1/*1 genotype, 2.38ng/ml for CYP2A6*1/*4, and 1.56ng/ml for CYP2A6*4/*4, respectively. Cotinine 65-73 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 147-153 24163286-9 2014 Strikingly, self-reported SHS-exposed women with CYP2A6*1/*4 or CYP2A6*4/*4 genotype had significantly lower (rather than higher) median cotinine levels than self-reported non-SHS-exposed women with CYP2A6*1/*1 genotype (p = .012). Cotinine 137-145 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 49-55 24163286-9 2014 Strikingly, self-reported SHS-exposed women with CYP2A6*1/*4 or CYP2A6*4/*4 genotype had significantly lower (rather than higher) median cotinine levels than self-reported non-SHS-exposed women with CYP2A6*1/*1 genotype (p = .012). Cotinine 137-145 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 64-70 24163286-9 2014 Strikingly, self-reported SHS-exposed women with CYP2A6*1/*4 or CYP2A6*4/*4 genotype had significantly lower (rather than higher) median cotinine levels than self-reported non-SHS-exposed women with CYP2A6*1/*1 genotype (p = .012). Cotinine 137-145 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 64-70 24163286-10 2014 CONCLUSIONS: CYP2A6*4 genotype is associated with lower serum cotinine among Chinese nonsmoking pregnant women. Cotinine 62-70 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 13-19 24163286-11 2014 Measuring CYP2A6*4 genotype may help to improve the validity of SHS exposure measurement by serum cotinine in pregnant women and possibly also in other nonpregnant populations. Cotinine 98-106 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 10-16 23674838-1 2013 INTRODUCTION: The nicotine metabolite ratio (NMR), the ratio of trans-3"-hydroxycotinine (3-HC) to cotinine, has been used as a biomarker of the rate of CYP2A6-mediated nicotine metabolism. Cotinine 80-88 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 153-159 23714690-0 2013 CYP2A6 genotype but not age determines cotinine half-life in infants and children. Cotinine 39-47 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 23714690-1 2013 The formation of cotinine, the main proximate metabolite and a biomarker of nicotine exposure, is mediated primarily by cytochrome P450 (CYP)2A6. Cotinine 17-25 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 137-144 23936477-1 2013 BACKGROUND: CYP2A6 metabolizes nicotine to its primary metabolite cotinine and also mediates the metabolism of cotinine to trans-3"-hydroxycotinine (3HC). Cotinine 111-119 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 12-18 23936477-2 2013 The ratio of 3HC to cotinine (the "nicotine metabolite ratio", NMR) is an in vivo marker for the rate of CYP2A6 mediated nicotine metabolism, and total nicotine clearance, and has been associated with differences in numerous smoking behaviors. Cotinine 20-28 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 105-111 23371292-0 2013 The ability of plasma cotinine to predict nicotine and carcinogen exposure is altered by differences in CYP2A6: the influence of genetics, race, and sex. Cotinine 22-30 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 104-110 23530019-7 2013 In humans, cytochrome P450 2A6 metabolizes nicotine to cotinine, and CYP2A-like activity and protein have been reported in some birds. Cotinine 55-63 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 11-30 23371292-3 2013 METHODS: Cotinine levels are determined by the amount of cotinine formation and the rate of cotinine removal, which are both mediated by the enzyme CYP2A6. Cotinine 9-17 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 148-154 23371292-3 2013 METHODS: Cotinine levels are determined by the amount of cotinine formation and the rate of cotinine removal, which are both mediated by the enzyme CYP2A6. Cotinine 57-65 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 148-154 23371292-3 2013 METHODS: Cotinine levels are determined by the amount of cotinine formation and the rate of cotinine removal, which are both mediated by the enzyme CYP2A6. Cotinine 92-100 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 148-154 23371292-4 2013 Because CYP2A6 activity differs by sex (estrogen induces CYP2A6) and genotype, their effect on cotinine formation and removal was measured in nonsmoking Caucasians (Study 1, n = 181) infused with labeled nicotine and cotinine. Cotinine 95-103 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 8-14 23371292-6 2013 RESULTS: Study 1: Reduced CYP2A6 activity altered cotinine formation less than cotinine removal resulting in ratios of formation to removal of 1.31 and 1.12 in CYP2A6 reduced and normal metabolizers (P = 0.01), or 1.39 and 1.12 in males and females (P = 0.001), suggesting an overestimation of tobacco exposure in slower metabolizers. Cotinine 50-58 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 26-32 23371292-7 2013 Study 2: Cotinine again overestimated tobacco and carcinogen exposure by 25% or more in CYP2A6 reduced metabolizers ( 2-fold between some genotypes) and in males. Cotinine 9-17 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 88-94 23371292-8 2013 CONCLUSIONS: In people with slower relative to faster CYP2A6 activity, cotinine accumulates resulting in substantial differences in cotinine levels for a given tobacco exposure. Cotinine 71-79 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 54-60 23371292-8 2013 CONCLUSIONS: In people with slower relative to faster CYP2A6 activity, cotinine accumulates resulting in substantial differences in cotinine levels for a given tobacco exposure. Cotinine 132-140 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 54-60 23371292-9 2013 IMPACT: Cotinine levels may be misleading when comparing those with differing CYP2A6 genotypes within a race, between races with differing frequencies of CYP2A6 gene variants (i.e., African-Americans have higher frequencies of reduced function variants contributing to their higher cotinine levels), or between the sexes. Cotinine 8-16 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 78-84 23371292-9 2013 IMPACT: Cotinine levels may be misleading when comparing those with differing CYP2A6 genotypes within a race, between races with differing frequencies of CYP2A6 gene variants (i.e., African-Americans have higher frequencies of reduced function variants contributing to their higher cotinine levels), or between the sexes. Cotinine 8-16 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 154-160 23211429-3 2013 METHODS: A genetic model of CYP2A6 function is used as a covariate to reveal functional polymorphism in FMO3 that indirectly influences the ratio of deuterated nicotine metabolized to cotinine following oral administration. Cotinine 184-192 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 28-34 23211429-8 2013 Functional classes of FMO3 haplotypes, as determined by their influence on nicotine metabolism to cotinine, are also significantly associated with cigarettes per day in nicotine-dependent European Americans (n=1025, P=0.04), and significantly interact (P=0.016) with CYP2A6 genotype to predict cigarettes per day. Cotinine 98-106 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 267-273 22569203-6 2012 Nicotine metabolism [as measured by the plasma and urinary ratio of metabolites trans-3"-hydroxycotinine to cotinine (3HC/COT)] was significantly associated with CYP2A6 (P<0.001), but not CYP2B6 genotype (P=0.95) when controlling for known covariates. Cotinine 96-104 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 162-168 23027621-1 2013 Nicotine, the psychoactive ingredient in tobacco, is metabolically inactivated by CYP2A6 to cotinine. Cotinine 92-100 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 82-88 22938167-6 2012 The 3-hydroxycotinine-to-cotinine ratio, a marker of cytochrome P450 2A6 (CYP2A6) metabolic activity, was significantly higher in BPD versus CON and versus SCZ (0.68 versus 0.49 versus 0.54; p =0.002). Cotinine 13-21 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 53-72 22938167-6 2012 The 3-hydroxycotinine-to-cotinine ratio, a marker of cytochrome P450 2A6 (CYP2A6) metabolic activity, was significantly higher in BPD versus CON and versus SCZ (0.68 versus 0.49 versus 0.54; p =0.002). Cotinine 13-21 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 74-80 22218454-3 2012 OBJECTIVES: We tested substituted heteroaromatic compounds designed to selectively inhibit hCYP 2A6 in a model system to (a) examine selective hCYP 2A6 inhibitors to decrease cotinine formation in vivo in rats administered with nicotine and (b) examine their efficacy to decrease nicotine self-administration in rats. Cotinine 175-183 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 143-151 22498344-10 2012 Nicotine metabolism and ROS formation by CYP2A6 were further confirmed by using tryptamine, a selective inhibitor of CYP2A6, which significantly lowered the levels of cotinine and NNK and inhibited ROS formation. Cotinine 167-175 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 41-47 22498344-10 2012 Nicotine metabolism and ROS formation by CYP2A6 were further confirmed by using tryptamine, a selective inhibitor of CYP2A6, which significantly lowered the levels of cotinine and NNK and inhibited ROS formation. Cotinine 167-175 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 117-123 22552800-1 2012 BACKGROUND: The nicotine metabolite ratio (NMR or 3-hydroxycotinine/cotinine) has been used to phenotype CYP2A6-mediated nicotine metabolism. Cotinine 59-67 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 105-111 22382327-1 2012 Cytochrome P450 2A6 (CYP2A6) catalyzes important metabolic reactions of many xenobiotic compounds, including coumarin, nicotine, cotinine, and clinical drugs. Cotinine 129-137 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-19 22382327-1 2012 Cytochrome P450 2A6 (CYP2A6) catalyzes important metabolic reactions of many xenobiotic compounds, including coumarin, nicotine, cotinine, and clinical drugs. Cotinine 129-137 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 21-27 21919071-6 2011 However, individual variability of CYP2A6 allele,in which nicotine is catalyzed to cotinine, affects the level of urinary cotinine. Cotinine 83-91 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 35-41 21964962-11 2011 Structural equation modeling indicated that CYP2A6 moderation of smoking quantity risk on T2DM was mediated by the effects on serum cotinine, abdominal obesity, insulin resistance, and insulin secretion. Cotinine 132-140 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 44-50 21597399-1 2011 OBJECTIVE: To study the association between cytochrome P450 2A6 (CYP2A6) genotype and metabolism of nicotine to cotinine, identify functional polymorphisms, and develop a predictive genetic model of nicotine metabolism. Cotinine 112-120 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 44-63 21597399-1 2011 OBJECTIVE: To study the association between cytochrome P450 2A6 (CYP2A6) genotype and metabolism of nicotine to cotinine, identify functional polymorphisms, and develop a predictive genetic model of nicotine metabolism. Cotinine 112-120 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 65-71 21597399-8 2011 CONCLUSION: Among European-Americans, seven polymorphisms in the CYP2A6 gene explain the majority of variability in the metabolism of nicotine to cotinine after oral administration. Cotinine 146-154 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 65-71 21919071-6 2011 However, individual variability of CYP2A6 allele,in which nicotine is catalyzed to cotinine, affects the level of urinary cotinine. Cotinine 122-130 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 35-41 20438369-7 2010 The results indicated that cumulative urinary cotinine excretion in CYP2A6*4 genotype was about one-eighth compared with the control group (wild type). Cotinine 46-54 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 68-74 20719908-3 2010 The ratio of 3HC to cotinine was calculated as a marker of CYP2A6 metabolic activity. Cotinine 20-28 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 59-65 20438369-8 2010 Cotinine formation from nicotine has individual and ethnic variability that correlated with the level of CYP2A6 expression. Cotinine 0-8 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 105-111 20438369-9 2010 Moreover, urinary cotinine level was drastically lower in CYP2A6*4 subjects than in CYP2A6*1 subjects. Cotinine 18-26 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 58-64 20438369-9 2010 Moreover, urinary cotinine level was drastically lower in CYP2A6*4 subjects than in CYP2A6*1 subjects. Cotinine 18-26 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 84-90 18779312-2 2008 A number of compounds, including nicotine, cotinine, and aflatoxin B(1), are metabolites of the 94% identical CYP2A13 and CYP2A6 enzymes but at different rates. Cotinine 43-51 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 122-128 19029401-5 2008 We assessed CYP2A6 activity by nicotine metabolite ratio (total trans-3-hydroxycotinine/total cotinine) and caffeine metabolite ratio (1,7-dimethyl uric acid/1,7-dimethylxanthine) in 12 h urine. Cotinine 79-87 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 12-18 18559554-1 2008 BACKGROUND: The ratio of two nicotine metabolites, cotinine and trans-3"-hydroxycotinine (3-HC), has been validated as a method of phenotyping the activity of the liver enzyme cytochrome P450 (CYP) 2A6 and, thus, the rate of nicotine metabolism. Cotinine 51-59 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 176-201 18216723-8 2008 The trans-3"-hydroxycotinine to cotinine ratio, a phenotypic measure of CYP2A6 activity in vivo, was lower in CYP2A6*1/*23 and CYP2A6*23/*23 individuals (mean adjusted ratio of 0.60, n=5) compared with CYP2A6*1/*1 individuals (mean adjusted ratio of 1.21, n=150) (P<0.04). Cotinine 20-28 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 72-78 18360915-1 2008 Cytochrome P450 2A6 (CYP2A6) is a human enzyme best known for metabolizing tobacco-related compounds, such as nicotine, cotinine (COT), and nitrosamine procarcinogens. Cotinine 120-128 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-19 18360915-1 2008 Cytochrome P450 2A6 (CYP2A6) is a human enzyme best known for metabolizing tobacco-related compounds, such as nicotine, cotinine (COT), and nitrosamine procarcinogens. Cotinine 120-128 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 21-27 18360915-1 2008 Cytochrome P450 2A6 (CYP2A6) is a human enzyme best known for metabolizing tobacco-related compounds, such as nicotine, cotinine (COT), and nitrosamine procarcinogens. Cotinine 130-133 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-19 18360915-1 2008 Cytochrome P450 2A6 (CYP2A6) is a human enzyme best known for metabolizing tobacco-related compounds, such as nicotine, cotinine (COT), and nitrosamine procarcinogens. Cotinine 130-133 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 21-27 18216723-8 2008 The trans-3"-hydroxycotinine to cotinine ratio, a phenotypic measure of CYP2A6 activity in vivo, was lower in CYP2A6*1/*23 and CYP2A6*23/*23 individuals (mean adjusted ratio of 0.60, n=5) compared with CYP2A6*1/*1 individuals (mean adjusted ratio of 1.21, n=150) (P<0.04). Cotinine 20-28 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 110-116 18216723-8 2008 The trans-3"-hydroxycotinine to cotinine ratio, a phenotypic measure of CYP2A6 activity in vivo, was lower in CYP2A6*1/*23 and CYP2A6*23/*23 individuals (mean adjusted ratio of 0.60, n=5) compared with CYP2A6*1/*1 individuals (mean adjusted ratio of 1.21, n=150) (P<0.04). Cotinine 20-28 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 110-116 18216723-8 2008 The trans-3"-hydroxycotinine to cotinine ratio, a phenotypic measure of CYP2A6 activity in vivo, was lower in CYP2A6*1/*23 and CYP2A6*23/*23 individuals (mean adjusted ratio of 0.60, n=5) compared with CYP2A6*1/*1 individuals (mean adjusted ratio of 1.21, n=150) (P<0.04). Cotinine 20-28 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 110-116 17979512-3 2007 Cytochrome P450 (CYP)2A6 is the human hepatic enzyme that mediates most of nicotine"s metabolic inactivation to cotinine. Cotinine 112-120 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-24 18041664-3 2007 The absorbed nicotine is rapidly and extensively metabolized to inactive cotinine by CYP2A6 in human livers, which has a major impact on nicotine clearance. Cotinine 73-81 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 85-91 17237153-1 2007 Human CYP2A6 catalyzes the metabolism of nicotine, cotinine, and coumarin as well as some pharmaceutical drugs. Cotinine 51-59 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 6-12 17267622-4 2007 The plasma cotinine/nicotine ratio in subjects possessing the novel CYP2A6 gene duplication with the CYP2A6*1 allele (10.8 +/- 7.0, n = 4) was 1.4-fold higher than that in homozygotes of the wild type (8.0 +/- 5.0, n = 87), although the difference was not statistically significant. Cotinine 11-19 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 101-107 17267622-4 2007 The plasma cotinine/nicotine ratio in subjects possessing the novel CYP2A6 gene duplication with the CYP2A6*1 allele (10.8 +/- 7.0, n = 4) was 1.4-fold higher than that in homozygotes of the wild type (8.0 +/- 5.0, n = 87), although the difference was not statistically significant. Cotinine 11-19 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 68-74 17237153-4 2007 We found that coumarin 7-hydroxylation and cotinine 3"-hydroxylation by recombinant CYP2A6 expressed in baculovirus-infected insect cells were competitively inhibited by tryptamine (both K(i) = 0.2 microM), serotonin (K(i) = 252 microM and 167 microM), dopamine (K(i) = 49 microM and 22 microM), and histamine (K(i) = 428 microM and 359 microM). Cotinine 43-51 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 84-90 16636685-1 2006 Human cytochrome P450 (CYP) 2A6 metabolizes nicotine to cotinine. Cotinine 56-64 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 6-31 17178771-1 2007 Human cytochrome CYP2A13 shows overlapping substrate specificity with CYP2A6, catalyzing the metabolism of coumarin, nicotine, cotinine, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone. Cotinine 127-135 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 70-76 17112802-6 2006 RESULTS: On the basis of the fractional clearance of nicotine to cotinine and on the plasma ratio of 3"-hydroxycotinine to cotinine, both shown to be indicators of CYP2A6 enzymatic activity, subjects were classified into 3 groups. Cotinine 111-119 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 164-170 17454704-12 2007 This study showed that hormonal contraception in adolescent girls may accelerate cotinine metabolism, an effect likely related to induction of cytochrome P450 2A6 and independent of ethnicity and cigarette consumption. Cotinine 81-89 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 143-162 17220563-7 2006 Subjects having CYP2A6*1A/*1B were found to have a higher rate of 7-OHC excretion, as well as a higher cotinine/nicotine ratio in the plasma compared with those of the other genotypes. Cotinine 103-111 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 16-22 17220563-8 2006 In contrast, subjects with CYP2A6*4/*7 and CYP2A6*7/*7 almost lacked any cotinine formation, whereas urinary 7-OHC was still detectable. Cotinine 73-81 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 27-33 17220563-8 2006 In contrast, subjects with CYP2A6*4/*7 and CYP2A6*7/*7 almost lacked any cotinine formation, whereas urinary 7-OHC was still detectable. Cotinine 73-81 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 43-49 16765148-1 2006 BACKGROUND: Nicotine is metabolized to cotinine, and cotinine is metabolized to 3"-hydroxycotinine (3-HC) by the liver enzyme cytochrome P450 (CYP) 2A6. Cotinine 53-61 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 126-151 17035386-1 2006 CYP2A6 inactivates nicotine to cotinine and cotinine to 3-hydroxycotinine. Cotinine 31-39 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 17035386-1 2006 CYP2A6 inactivates nicotine to cotinine and cotinine to 3-hydroxycotinine. Cotinine 44-52 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 17035386-5 2006 3-Hydroxycotinine/cotinine is reported to be a good marker of CYP2A6 activity, and we found that the 3-hydroxycotinine/(cotinine + nicotine) ratio was most correlated with CYP2A6 genotype (r = 0.38, P < 0.001). Cotinine 9-17 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 62-68 17035386-5 2006 3-Hydroxycotinine/cotinine is reported to be a good marker of CYP2A6 activity, and we found that the 3-hydroxycotinine/(cotinine + nicotine) ratio was most correlated with CYP2A6 genotype (r = 0.38, P < 0.001). Cotinine 9-17 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 172-178 17035386-5 2006 3-Hydroxycotinine/cotinine is reported to be a good marker of CYP2A6 activity, and we found that the 3-hydroxycotinine/(cotinine + nicotine) ratio was most correlated with CYP2A6 genotype (r = 0.38, P < 0.001). Cotinine 18-26 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 62-68 17035386-8 2006 Here, we found that plasma nicotine levels were inversely correlated with CYP2A6 activity (3-hydroxycotinine/cotinine, r = -0.41, P < 0.001) among those without CYP2A6 variants, suggesting a reduction in metabolism with higher nicotine levels. Cotinine 100-108 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 74-80 17035386-9 2006 Together, these findings (a) confirm the use of plasma cotinine and CO as indicators of Caucasians" smoking levels, and that this is not limited by CYP2A6 genetic variation; (b) indicate that 3-hydroxycotinine/cotinine and 3-hydroxycotinine/(cotinine + nicotine) are moderately good indicators of the CYP2A6 genotype; and (c) support that nicotine exposure may reduce its own metabolism. Cotinine 201-209 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 301-307 17035386-9 2006 Together, these findings (a) confirm the use of plasma cotinine and CO as indicators of Caucasians" smoking levels, and that this is not limited by CYP2A6 genetic variation; (b) indicate that 3-hydroxycotinine/cotinine and 3-hydroxycotinine/(cotinine + nicotine) are moderately good indicators of the CYP2A6 genotype; and (c) support that nicotine exposure may reduce its own metabolism. Cotinine 201-209 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 301-307 16952495-1 2006 Human cytochrome P450 (CYP) 2A6 metabolizes nicotine to cotinine and is a possible modulator of nicotine addiction. Cotinine 56-64 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 6-31 16402128-2 2006 Caucasian smokers with CYP2A6 slow vs normal metabolism had lower metabolic activity, indicated by the 3-hydroxycotinine/cotinine ratio (0.23+/-0.17 vs 0.45+/-0.22, P<0.01, respectively). Cotinine 112-120 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 23-29 16372023-2 2005 METHODS: The procedure involved (a) genotyping 85 Maori participants for cytochrome P-450 2A6 (CYP2A6) gene variants, which are associated with reduced nicotine metabolic rate (ie CYP2A6*9 and *4); and (b) measuring salivary cotinine (COT) and trans-3"-hydroxycotinine (3-HC) as biomarkers of nicotine intake and metabolic rate in 12 female smokers from the Hawke"s Bay Region (6 Maori and 6 European). Cotinine 225-233 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 95-101 16402086-1 2006 CYP2A6 is the main enzyme that catalyzes nicotine into cotinine. Cotinine 55-63 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 16141602-10 2005 There are substantial data suggesting that the large interindividual differences in cotinine formation are associated with genetic polymorphisms of the CYP2A6 gene. Cotinine 84-92 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 152-158 16359169-0 2005 Identification of N-(hydroxymethyl) norcotinine as a major product of cytochrome P450 2A6, but not cytochrome P450 2A13-catalyzed cotinine metabolism. Cotinine 39-47 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 70-89 16272956-2 2005 Mutations in CYP2A6 slow metabolism of nicotine to cotinine. Cotinine 51-59 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 13-19 15998359-1 2005 CYP2A6 in man catalyzes the oxidation of nicotine-forming cotinine and 7-hydroxylation of coumarin, which is used as test substrate for CYP2A6 in man. Cotinine 58-66 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 15998359-1 2005 CYP2A6 in man catalyzes the oxidation of nicotine-forming cotinine and 7-hydroxylation of coumarin, which is used as test substrate for CYP2A6 in man. Cotinine 58-66 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 136-142 16141602-3 2005 A major pathway of nicotine metabolism is C-oxidation to cotinine, which is catalyzed by CYP2A6 in human livers. Cotinine 57-65 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 89-95 16141602-4 2005 Cotinine is subsequently metabolized to trans-3"-hydroxycotinine by CYP2A6. Cotinine 0-8 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 68-74 14577978-3 2003 Nicotine is metabolized extensively by the liver enzyme CYP2A6, primarily to cotinine. Cotinine 77-85 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 56-62 15265511-8 2004 In contrast, in two subjects with CYP2A6*4/CYP2A6*4 (group II), trace levels of cotinine, cotinine N-glucuronide, and cotinine 1"-N-oxide were detected. Cotinine 80-88 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 34-40 15265511-8 2004 In contrast, in two subjects with CYP2A6*4/CYP2A6*4 (group II), trace levels of cotinine, cotinine N-glucuronide, and cotinine 1"-N-oxide were detected. Cotinine 80-88 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 43-49 15225612-2 2004 CYP2A6 also catalyzes nicotine C-oxidation leading to cotinine formation, a major metabolic pathway of nicotine in humans. Cotinine 54-62 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 15940289-6 2005 The subjects carrying the CYP2A6*1B allele oxidize nicotine to cotinine faster than subjects with the CYP2A6*1A allele. Cotinine 63-71 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 26-32 15592323-18 2004 Furthermore, cotinine/nicotine ratios after 1 piece of nicotine gum was chewed, used as an index of in vivo nicotine metabolism, were significantly (P < .05) decreased in heterozygotes of the CYP2A6*17 allele (5.4 +/- 2.7, n = 12) compared with homozygotes of the wild type (11.5 +/- 10.5, n = 37). Cotinine 13-21 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 195-201 15592323-19 2004 A subject with CYP2A6*17 / CYP2A6*17 revealed the lowest cotinine/nicotine ratio (1.8). Cotinine 57-65 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 15-21 15592323-19 2004 A subject with CYP2A6*17 / CYP2A6*17 revealed the lowest cotinine/nicotine ratio (1.8). Cotinine 57-65 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 27-33 15265511-1 2004 Generally, 70-80% of absorbed nicotine is mainly metabolized to cotinine by cytochrome P450 (CYP) 2A6. Cotinine 64-72 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 76-101 14577978-4 2003 Cotinine is itself metabolized by CYP2A6 to 3"-hydroxycotinine (3-HC). Cotinine 0-8 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 34-40 14577978-5 2003 The ratio of metabolite to parent (i.e., 3-HC:cotinine) would be expected to reflect CYP2A6 activity. Cotinine 46-54 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 85-91 12504349-2 2003 Hepatic cytochrome P4502A6 (CYP2A6) catalyses the major route of nicotine metabolism: C-oxidation to cotinine, followed by hydroxylation to trans-3"-hydroxycotinine. Cotinine 101-109 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 28-34 12844137-1 2003 Cytochrome P450 (CYP) 2A6 catalyzes nicotine C-oxidation, leading to cotinine formation, a major metabolic pathway of nicotine in humans. Cotinine 69-77 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-25 12844137-8 2003 In Korean subjects the cotinine/nicotine ratios as an index of nicotine metabolism in the subjects with CYP2A6*9/CYP2A6*9 (4.3 +/- 2.4) were significantly lower than those in the subjects with CYP2A6*1A/CYP2A6*9 (7.7 +/- 5.6) and CYP2A6*1A/CYP2A6*1A (10.4 +/- 9.2) (P <.05 and P <.005, respectively). Cotinine 23-31 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 104-110 12844137-8 2003 In Korean subjects the cotinine/nicotine ratios as an index of nicotine metabolism in the subjects with CYP2A6*9/CYP2A6*9 (4.3 +/- 2.4) were significantly lower than those in the subjects with CYP2A6*1A/CYP2A6*9 (7.7 +/- 5.6) and CYP2A6*1A/CYP2A6*1A (10.4 +/- 9.2) (P <.05 and P <.005, respectively). Cotinine 23-31 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 113-119 12844137-8 2003 In Korean subjects the cotinine/nicotine ratios as an index of nicotine metabolism in the subjects with CYP2A6*9/CYP2A6*9 (4.3 +/- 2.4) were significantly lower than those in the subjects with CYP2A6*1A/CYP2A6*9 (7.7 +/- 5.6) and CYP2A6*1A/CYP2A6*1A (10.4 +/- 9.2) (P <.05 and P <.005, respectively). Cotinine 23-31 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 113-119 12844137-8 2003 In Korean subjects the cotinine/nicotine ratios as an index of nicotine metabolism in the subjects with CYP2A6*9/CYP2A6*9 (4.3 +/- 2.4) were significantly lower than those in the subjects with CYP2A6*1A/CYP2A6*9 (7.7 +/- 5.6) and CYP2A6*1A/CYP2A6*1A (10.4 +/- 9.2) (P <.05 and P <.005, respectively). Cotinine 23-31 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 113-119 12844137-8 2003 In Korean subjects the cotinine/nicotine ratios as an index of nicotine metabolism in the subjects with CYP2A6*9/CYP2A6*9 (4.3 +/- 2.4) were significantly lower than those in the subjects with CYP2A6*1A/CYP2A6*9 (7.7 +/- 5.6) and CYP2A6*1A/CYP2A6*1A (10.4 +/- 9.2) (P <.05 and P <.005, respectively). Cotinine 23-31 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 113-119 12844137-8 2003 In Korean subjects the cotinine/nicotine ratios as an index of nicotine metabolism in the subjects with CYP2A6*9/CYP2A6*9 (4.3 +/- 2.4) were significantly lower than those in the subjects with CYP2A6*1A/CYP2A6*9 (7.7 +/- 5.6) and CYP2A6*1A/CYP2A6*1A (10.4 +/- 9.2) (P <.05 and P <.005, respectively). Cotinine 23-31 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 113-119 11805739-3 2002 The genetically polymorphic CYP2A6 enzyme is responsible for the majority of the metabolic inactivation of nicotine to cotinine (12-14). Cotinine 119-127 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 28-34 12487152-3 2002 Nicotine is mainly metabolized to cotinine by cytochrome P450 (CYP) 2A6. Cotinine 34-42 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 46-71 12024803-3 2002 In whole deletion of CYP2A6, urinary excretion amounts of cotinine and trans-3"-hydroxycotinine were significantly smaller than those in the wild-type of CYP2A6*1. Cotinine 58-66 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 21-27 12024803-4 2002 A lack of CYP2A6 reduces the formation of cotinine and trans-3"-hydroxycotinine, but not entirely reduces the trans-3"-hydroxycotinine formation. Cotinine 42-50 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 10-16 12488541-2 2003 Nicotine is inactivated to cotinine by CYP2A6 in human liver [nicotine C-oxidation (NCO)]. Cotinine 27-35 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 39-45 12406643-5 2002 The resulting interindividual variation in metabolic activity may affect the metabolism of CYP2A6 substrates including nicotine, cotinine (the major metabolite of nicotine), several tobacco-specific procarcinogens, coumarin and many toxins. Cotinine 129-137 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 91-97 11353760-1 2001 CYP2A6 is the principle enzyme metabolizing nicotine to its inactive metabolite cotinine. Cotinine 80-88 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 11401907-8 2001 The number of cigarettes smoked and CYP2A6 polymorphism were significantly associated with the urinary cotinine level. Cotinine 103-111 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 36-42 11401907-9 2001 Especially, the urinary cotinine levels was drastically lower in CYP2A6-deleted homozygous (CYP2A6*4/*4) subjects than in CYP2A6*1 allele-positive subjects. Cotinine 24-32 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 65-71 11401907-9 2001 Especially, the urinary cotinine levels was drastically lower in CYP2A6-deleted homozygous (CYP2A6*4/*4) subjects than in CYP2A6*1 allele-positive subjects. Cotinine 24-32 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 92-98 11401907-9 2001 Especially, the urinary cotinine levels was drastically lower in CYP2A6-deleted homozygous (CYP2A6*4/*4) subjects than in CYP2A6*1 allele-positive subjects. Cotinine 24-32 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 92-98 11434509-1 2001 CYP2A6 is a major catalyst of nicotine metabolism to cotinine. Cotinine 53-61 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 11434509-8 2001 The homozygotes of the CYP2A6*4 allele (four subjects) were completely deficient in cotinine formation, being consistent with the data among Japanese. Cotinine 84-92 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 23-29 11434509-10 2001 The subjects who possess the CYP2A6*1B allele appeared to show higher capabilities of cotinine formation. Cotinine 86-94 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 29-35 11259349-2 2001 In humans, 70 to 80% of nicotine is metabolized to the inactive metabolite cotinine by the enzyme CYP2A6. Cotinine 75-83 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 98-104 11180041-1 2001 BACKGROUND: Nicotine is mainly metabolized to cotinine by cytochrome P450 (CYP) 2A6. Cotinine 46-54 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 58-83 11180041-2 2001 Previously, we found that the CYP2A6 gene was deleted homozygously in one subject who was deficient in cotinine formation from nicotine. Cotinine 103-111 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 30-36 11180041-10 2001 Three subjects genotyped as CYP2A6*4/CYP2A6*4 were completely deficient in cotinine formation. Cotinine 75-83 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 28-34 11180041-10 2001 Three subjects genotyped as CYP2A6*4/CYP2A6*4 were completely deficient in cotinine formation. Cotinine 75-83 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 37-43 11180041-11 2001 The heterozygotes of the CYP2A6*4 allele tend to show lower capacities for cotinine formation. Cotinine 75-83 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 25-31 11180041-12 2001 The subjects with CYP2A6*1A/CYP2A6*1B appeared to have higher capacities of cotinine formation than subjects with CYP2A6*1A/CYP2A6*1A, although the difference was not significant. Cotinine 76-84 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 18-24 11180041-12 2001 The subjects with CYP2A6*1A/CYP2A6*1B appeared to have higher capacities of cotinine formation than subjects with CYP2A6*1A/CYP2A6*1A, although the difference was not significant. Cotinine 76-84 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 28-34 11180041-12 2001 The subjects with CYP2A6*1A/CYP2A6*1B appeared to have higher capacities of cotinine formation than subjects with CYP2A6*1A/CYP2A6*1A, although the difference was not significant. Cotinine 76-84 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 28-34 11180041-12 2001 The subjects with CYP2A6*1A/CYP2A6*1B appeared to have higher capacities of cotinine formation than subjects with CYP2A6*1A/CYP2A6*1A, although the difference was not significant. Cotinine 76-84 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 28-34 11180041-13 2001 The probit plot of the cotinine-nicotine ratio was not linear; this possibly indicated the existence of a novel mutation in the CYP2A6 gene genotyped as CYP2A6*1B/CYP2A6*4. Cotinine 23-31 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 128-134 11180041-13 2001 The probit plot of the cotinine-nicotine ratio was not linear; this possibly indicated the existence of a novel mutation in the CYP2A6 gene genotyped as CYP2A6*1B/CYP2A6*4. Cotinine 23-31 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 153-159 11180041-13 2001 The probit plot of the cotinine-nicotine ratio was not linear; this possibly indicated the existence of a novel mutation in the CYP2A6 gene genotyped as CYP2A6*1B/CYP2A6*4. Cotinine 23-31 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 153-159 10668854-0 2000 Deficient cotinine formation from nicotine is attributed to the whole deletion of the CYP2A6 gene in humans. Cotinine 10-18 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 86-92 10999944-1 2000 In humans, 80% of nicotine is metabolized to the inactive metabolite cotinine by the enzyme CYP2A6, which can also activate tobacco smoke procarcinogens (e.g., 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone). Cotinine 69-77 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 92-98 10781881-3 2000 CYP2A6 is a major contributor to the oxidative metabolism of nicotine and cotinine, and it also contributes, to a larger or smaller extent, to the metabolism of a few pharmaceuticals (e.g. fadrozole), nitrosamines, other carcinogens (e.g. aflatoxin B1) and a number of coumarin-type alkaloids. Cotinine 74-82 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 10668854-1 2000 Nicotine is mainly metabolized to cotinine by cytochrome P450 (CYP) 2A6. Cotinine 34-42 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 46-71 33375250-2 2020 One susceptibility gene to nicotine dependence is Cytochrome P450 (CYP) 2A6, an enzyme responsible for the conversion of nicotine to cotinine in the liver. Cotinine 133-141 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 50-75 9316878-7 1997 CYP2A6 appears to be the major P450 involved in human nicotine metabolism to cotinine. Cotinine 77-85 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 0-6 9316878-8 1997 Coumarin, a specific and selective CYP2A6 substrate, competitively inhibited cotinine formation by 85 +/- 11% (mean +/- S.D.) Cotinine 77-85 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 35-41 9316878-10 1997 The K(i) value for this inhibition ranged from 1 to 5 microM, and a CYP2A6 monoclonal antibody inhibited cotinine formation by >75%. Cotinine 105-113 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 68-74 9316878-11 1997 Immunochemically determined CYP2A6 correlated significantly with nicotine-to-cotinine V(max) values (r = .90, n = 30, P < .001) and to inhibition of nicotine metabolism by coumarin (r = .94, n = 30, P < .001). Cotinine 77-85 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 28-34 8937855-4 1996 Cotinine formation in human liver microsomes significantly correlated with immunochemically determined CYP2A6 levels (r = 0.663, p < 0.05), coumarin 7-hydroxylase activities (r = 0.831, p < 0.01), and cotinine 3"-hydroxylase activities (r = 0.735, p < 0.01) that are responsible for CYP2A6. Cotinine 0-8 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 103-109 8937855-4 1996 Cotinine formation in human liver microsomes significantly correlated with immunochemically determined CYP2A6 levels (r = 0.663, p < 0.05), coumarin 7-hydroxylase activities (r = 0.831, p < 0.01), and cotinine 3"-hydroxylase activities (r = 0.735, p < 0.01) that are responsible for CYP2A6. Cotinine 0-8 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 143-165 8937855-4 1996 Cotinine formation in human liver microsomes significantly correlated with immunochemically determined CYP2A6 levels (r = 0.663, p < 0.05), coumarin 7-hydroxylase activities (r = 0.831, p < 0.01), and cotinine 3"-hydroxylase activities (r = 0.735, p < 0.01) that are responsible for CYP2A6. Cotinine 0-8 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 292-298 8937855-6 1996 When the capability of microsomes of B-lymphoblastoid cells expressing human CYPs to perform biotransformation of nicotine to cotinine was determined, cDNA-expressed CYP2A6 exhibited the highest cotinine formation. Cotinine 126-134 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 166-172 8937855-6 1996 When the capability of microsomes of B-lymphoblastoid cells expressing human CYPs to perform biotransformation of nicotine to cotinine was determined, cDNA-expressed CYP2A6 exhibited the highest cotinine formation. Cotinine 195-203 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 166-172 8937855-8 1996 The large interindividual variabilities in cotinine formation and immunochemically determined CYP2A6 levels were observed in human liver microsomes, suggesting genetic polymorphism of CYP2A6. Cotinine 43-51 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 184-190 35197312-1 2022 The major mode of metabolism of nicotine is via the formation of cotinine by the enzyme cytochrome P450 (CYP) 2A6. Cotinine 65-73 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 88-113 35197312-2 2022 Cotinine undergoes further CYP2A6-mediated metabolism by hydroxylation to 3-hydroxycotinine and norcotinine but can also form cotinine-N-glucuronide and cotinine-N-oxide (COX). Cotinine 0-8 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 27-33 10565842-9 1999 We conclude that the metabolism of cotinine is slower in blacks than in whites because of both slower oxidative metabolism of nicotine to cotinine (presumably via cytochrome P-450 2A6) and slower N-glucuronidation. Cotinine 35-43 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 163-183 10448083-6 1999 Cumulated urinary cotinine excretion in the homozygously CYP2A6-deleted individuals was about one-seventh compared to the control group (wild type). Cotinine 18-26 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 57-63 8627511-0 1996 Characterization of CYP2A6 involved in 3"-hydroxylation of cotinine in human liver microsomes. Cotinine 59-67 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 20-26 8627511-9 1996 In conclusion, cotinine 3"-hydroxylation appears to be catalyzed solely by CYP2A6 in humans. Cotinine 15-23 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 75-81 8627511-10 1996 Cotinine is a candidate for a new substrate for CYP2A6 in humans. Cotinine 0-8 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 48-54 7646564-11 1995 The rate of (S)-cotinine formation at low (10 microM) concentration correlated well with immunoreactivity for cytochrome P450 2A6 (r = 0.89). Cotinine 12-24 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 110-129 30815984-1 2020 The nicotine metabolite ratio (NMR; 3-hydroxycotinine/cotinine) is an index of CYP2A6 activity. Cotinine 45-53 cytochrome P450 family 2 subfamily A member 6 Homo sapiens 79-85