Suppression of the purgative action of rhein anthrone, the active metabolite of sennosides A and B, by calcium channel blockers, calmodulin antagonists and indomethacin.
The involvement of Ca2+ in the mechanism of the purgative action of rhein anthrone was studied. Among individual or combination pretreatments with calcium channel blockers, calmodulin antagonists and prostaglandin biosynthesis inhibitors, the combination of indomethacin and nifedipine completely blocked the diarrhoea induced by rhein anthrone and also inhibited its effects on colonic fluid and electrolyte transport, and large intestinal motility. Calmodulin antagonists were less active regarding suppression of the effects of rhein anthrone. We concluded that, in addition to prostaglandins, diarrhoea induced by rhein anthrone must also involve the calcium channel which can be blocked by nifedipine, but not verapamil.
Yamauchi
K
K
Faculty of Pharmaceutical Sciences, Mukogawa Women's University, Nishinomiya, Japan.
Yagi
T
T
Kuwano
S
S
D000818:Animals; D000873:Anthracenes / Q000494:pharmacology; D000880:Anthraquinones / Q000037:antagonists & inhibitors / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002147:Calmodulin / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D002400:Cathartics / Q000494:pharmacology; D003106:Colon / Q000187:drug effects / Q000503:physiopathology; D003967:Diarrhea / Q000139:chemically induced / Q000503:physiopathology / Q000517:prevention & control*; D004359:Drug Therapy, Combination; D005260:Female; D005769:Gastrointestinal Motility / Q000187:drug effects; D005772:Gastrointestinal Transit / Q000187:drug effects; D007213:Indomethacin / Q000494:pharmacology*; D007419:Intestinal Secretions / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D012676:Senna Extract; D000081226:Sennosides; D000095322:Anthrones
D000873:Anthracenes; D000880:Anthraquinones; D002118:Calcium; D002121:Calcium Channel Blockers; D002147:Calmodulin; D002400:Cathartics; D007213:Indomethacin; D012676:Senna Extract; D000081226:Sennosides; C055876:rhein-9-anthrone; D000095322:Anthrones