PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 12086542-10 2002 Whether sildenafil causes these effects by inhibiting PDE-5 in the brain, accumulating cyclic-GMP, decreasing NO, and affecting cell-cell signaling and modulation of aggressive behavior requires further investigation. Sildenafil Citrate 8-18 phosphodiesterase 5A Homo sapiens 54-59