Stimulation of Autonomic Cholinoceptors in the Rat Uterus by a Crude Extract from Eleophorbia drupifera Leaves

Abstract

The crude extract from E. drupifera was tested for its effects on isolated rat uterine preparations. The extract (2.0-300 µg/ml) produced graded increases in uterine contractions. The contractions were potentiated by neostigmine (1.64 × 10 -6 M) and abolished by atropine (4.4 × 10 -4 M). The extract-induced contractions were not prevented by previous addition to the bath of hexamethonium or 5-hydroxytryptamine and bradykinin antagonist. However, extract-induced increase in uterine contraction was abolished by either lidocaine (4.2 × 10 -5 M) or tetrodotoxin (5 × 10 -8 M). These data seem to indicate that the crude extract-induced increase in myometrial contractility is due to actions on post-ganlionic autonomic nerve endings, with acetylcholine release and stimulation of muscarinic receptors.