A dual action of 5-hydroxytryptamine on the ovarian suspensory ligament of the rat

Abstract

5-Hydroxytryptamine has a dual effect on the spontaneously contracting rat ovarian ligament, in vitro, a contraction which is antagonized by the prior administration of methysergide and a relaxation of the ligament observed in the methysergide-treated preparation. The relaxatory effect was not antagonized by propranolol or tetrodotoxin but treatment of the ligament with indomethacin abolished this response. Prostaglandins of the E series produced an inhibition, and PGF2α; a contraction of the ligament. Thin layer chromatographic separation indicates that 5-HT causes the release of a PGE2-like substance which relaxes the ovarian suspensory ligament.