Biology of Reproduction, Vol 3, 163-168, Copyright © 1970 by Society for the Study of Reproduction

Some Effects of Prostaglandins E₂ and F₂ on the Pregnant Rhesus Monkey

¹ Fertility Research, The Upjohn Company, Kalamazoo, Michigan 49001

Prostaglandin E₂(PGE₂) or prostaglandin F₂ (PGF₂) was injected subcutaneously or infused intravenously into pregnant rhesus monkeys. Animals were between day 30 and 127 of pregnancy; pregnancy termination, serum progestin levels, and uterine contractility were parameters measured to determine efficacy. Subcutaneous injections of PGF₂ or PGE₂ terminated pregnancy in 8 of 13 animals when given between day 30 and 41 and beyond day 100 of pregnancy. Intravenous infusion terminated 3 of 7 animals between day 30 and 40 of pregnancy. Progestin levels were usually depressed within 24-48 hr after the initial administration of prostaglandin, whereas uterine contractility was increased within 20-30 min. Prostaglandin E₂ was about 10 times as potent as PGF₂ in causing uterine contractions; intravenous infusion of 0.8 and 8.0 µg/min, respectively, caused maximal uterine contractions during the latter half of pregnancy. The realtionship of these compounds to normal pregnant uterine physiology in the human and rhesus monkey is discussed.