Planta Medica · 1983 · 18 citations · 0 references
MedicineBiochemistryPharmacologyBiochemical PharmacologyExperimental PharmacologyPharmacodynamicsEnzyme InhibitionGastrointestinal PharmacologyUterotonic TherapyBiphasic Dose-response RelationshipsDirect Smooth Muscle RelaxantsProstaglandin ActivityProstaglandin InhibitorsProstaglandin Synthesis InhibitionSmooth Muscle ContractionUterine Smooth Muscle PhysiologyUterotonic Pharmacology
The aqueous-methanol extract of the seed of Abrus precatorius elicited a biphasic response on the field stimulated guinea-pig ileum, being inhibitory in low concentrations but excitatory in higher concentrations. The two activities were separable by Sephadex gel filtration. The excitatory exponent (E) contracted most smooth muscle including the uterus. Its actions were atropine-sensitive. The inhibitory fraction (I) also contracted the uterus but relaxed other smooth muscles. It was resistant to common pharmacological blocking agents but its actions on smooth muscle were inhibited by the prostaglandin synthetase inhibitor indomethacin.