title: Dual actions of prostacyclin (PGI2) on the rat pregnant uterus.
abstract: Using strips of rat pregnant uterus, treated with indomethacin to suppress spontaneous contractility, the oxytocic activity of prostacyclin was compared with other prostaglandins. A prostacyclin concentration of 32 ng/ml elicited uterine contractions in all experiments. In this respect prostacyclin was 80 times more active than 6-oxo-PGF1 alpha but less active than PGE2 or PGF2 alpha. Apart from a direct stimulant effect, prostacyclin also exhibited an indirect potentiating action. In threshold concentrations prostacyclin caused a 3-fold potentiation of threshold doses of oxytocin. A lesser 1.5-fold potentiation of PGE2 alpha was also observed. The implications of these findings in relation to prostacyclin playing a role in parturition are discussed.
mesh_terms: D000818:Animals; D004305:Dose-Response Relationship, Drug; D004357:Drug Synergism; D011464:Epoprostenol / Q000008:administration & dosage / Q000494:pharmacology*; D005260:Female; D066298:In Vitro Techniques; D007213:Indomethacin / Q000494:pharmacology; D010121:Oxytocin / Q000494:pharmacology; D011247:Pregnancy; D011453:Prostaglandins / Q000494:pharmacology*; D011459:Prostaglandins E, Synthetic / Q000008:administration & dosage / Q000494:pharmacology; D011461:Prostaglandins F, Synthetic / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D014590:Uterine Contraction / Q000187:drug effects*
chemical_list: D011453:Prostaglandins; D011459:Prostaglandins E, Synthetic; D011461:Prostaglandins F, Synthetic; D010121:Oxytocin; D011464:Epoprostenol; D007213:Indomethacin