The Effect of Prostaglandin F 2α on Ovarian and Plasma Progesterone Levels in the Pregnant Hamster 1

Abstract

Summary

The effect of prostaglandin F_2α (PGF_2α) on peripheral plasma and ovarian progesterone concentrations has been studied in pregnant hamsters. PGF_2α administered subcutaneously at a dose of 0.1 mg/day on days 5 through 7 post-coitus lowered both plasma and ovarian progesterone levels and terminated pregnancy in all animals. Ovaries from PGF_2α-treated hamsters showed histological evidence of luteal disorganization on days 6 and 7 post-coitus. A 10-fold increase in the dose of PGF_2α (1 mg/day) caused an indication of luteal breakdown within 5 hr of the initial treatment. Ovarian weights, plasma progesterone levels, and luteal morphology of females after treatment and pregnancy termination were similar to those of untreated cycling females. Exogenous progesterone maintained pregnancy in PGF_2α-treated females.