PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 10481832-10 1999 The lower alpha 2A-vs. alpha 2C-adrenoceptor selectivity ratio of clonidine and the affinity for alpha 1-adrenoceptors of clonidine may be responsible for the different action of these drugs on attention. Clonidine 66-75 adrenoceptor alpha 2C Homo sapiens 23-44