Studies on the involvement of prostaglandins in implantation in the rat

Abstract

Studies of prostaglandin (PG) production by uterine homogenates of rats in early pseudopregnancy and prgnancy showed that production of 6-oxo-PGF1.alpha., PGF2.alpha. peaked on day 5 of pseudopregnancy whereas only 6-oxo-PGF1.alpha. and PGE2 peaked on day 5 of pregnancy, the day of implantation. 6-Oxo-PGF1.alpha. was the major product in both reproductive states. Indomethacin treatment of rats during early pregnancy caused a delay in implantation, a significant reduction in uterine weight and a much reduced number or absence of implanted blastocysts in the uterus on day 9. Plasma progesterone levels were also significantly lower in indomethacin-treated, pregnant rats. These findings support roles for prostaglandins in implantation and in fetal development.