6533b827fe1ef96bd12870b8

RESEARCH PRODUCT

Comparative study of the rat uterine smooth muscle relaxant activity of three bisbenzyltetrahydroisoquinolines with tetrandrine

Elsa AnselmiDiego CortesZafra-polo McTormos Mj

subject

medicine.medical_specialtyMuscle RelaxationUterusPharmaceutical Sciencechemistry.chemical_elementIn Vitro TechniquesBiologyCalciumOxytocinBenzylisoquinolinesUterine contractionStructure-Activity RelationshipUterine Contractionchemistry.chemical_compoundAlkaloidsInternal medicinemedicineAnimalsVanadateRats WistarPharmacologyAlkaloidUterusMuscle SmoothCalcium Channel BlockersIsoquinolinesRatsTetrandrinemedicine.anatomical_structureMuscle relaxationEndocrinologyOxytocinchemistryPotassiumCalciumFemaleVanadatesmedicine.symptommedicine.drug

description

Abstract 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 Ca2+-free medium.

https://doi.org/10.1111/j.2042-7158.1993.tb05599.x