Comparative study of the rat uterine smooth muscle relaxant activity of three bisbenzyltetrahydroisoquinolines with tetrandrine.
The relaxant activity of three bisbenzyltetrahydroisoquinolines--obaberine, popisonine and lindoldhamine--was examined in rat isolated uterus and their inhibitory potencies were compared with that of tetrandrine. All alkaloids tested relaxed KCl-depolarized rat uterus and totally or partially inhibited oxytocin-induced rhythmic contractions. The degree of methylation of the free phenolic hydroxy groups and the loss of one diarylether bridge influence the potency of relaxant action of these alkaloids. Only alkaloids with absolute configuration 1R,1'S or 1R1'R acted intracellularly, promoting relaxation of contractile responses induced by oxytocin or vanadate in a Ca(2+)-free medium.
Zafra-Polo
M C
MC
Departamento de Farmacologia, Facultad de Farmacia, Universidad de Valencia, Spain.
Tormos
M J
MJ
Cortes
D
D
Anselmi
E
E
D000470:Alkaloids / Q000494:pharmacology*; D000818:Animals; D044182:Benzylisoquinolines; D002118:Calcium / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D007546:Isoquinolines / Q000494:pharmacology*; D009126:Muscle Relaxation / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D010121:Oxytocin / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D013329:Structure-Activity Relationship; D014590:Uterine Contraction / Q000187:drug effects*; D014599:Uterus / Q000502:physiology*; D014638:Vanadates / Q000494:pharmacology
D000470:Alkaloids; D044182:Benzylisoquinolines; D002121:Calcium Channel Blockers; D007546:Isoquinolines; C009438:tetrandrine; D014638:Vanadates; D010121:Oxytocin; D011188:Potassium; D002118:Calcium