Effect of Continuous Intrauterine Administration of Prostaglandin F_2α and Indomethacin on Fertilization of Rabbits

Summary

The effect of continuous intrauterine administration of prostaglandin F_2α (PGF_2α) or indomethacin or indomethacin together with PGF_2α and PGE₂ or vehicle on fertilization of rabbits was studied.

These substances and vehicle were delivered into the cornua of the uterus via an Alzet minipump for 11 days. The animals were inseminated vaginallly. Compared with controls (104 eggs of which 88.5% were fertilized) a reduction of the fertilization rate was observed with indomethacin (74 eggs of which 70% were fertilized). Exogenously added PGF_2α did not change the fertilization rate.

The administration of indomethacin together with PGE₂ raised the fertilization rate to 86% (63 eggs of which 54 were fertilized). The application of PGF_2α together with indomethacin showed a fertilization rate of 85% (59 eggs of which 50 were fertilized).

The indomethacin application was associated with a reduction of prostaglandin production in several tissues from the female genital tract, showing that indomethacin is taken up by the endometrium of the rabbit.

The ovary, oviduct, cervix and vagina were mainly affected by this treatment.

The route of transport of this drug is not known, however.

The reduction of the total number of eggs together with the decrease of the fertilization rate after indomethacin administration point towards multiregional sites of interference of prostaglandins in reproductive functions.

PGF_2α seems to be the more important factor since PGE₂ may be converted to PGF_2α in reproductive tissues.

Key-Words

Prostaglandin F_2α - Indomethacin - Fertilization of Rabbits