Effects of gonadotropin administration and transplantation of the pituitary gland on fertilization, early embryonic development and steroid hormone levels in immature rats.

概要

論文の詳細を見る
The effects of varying doses of gonadotropin (GTH) administration or thetransplantation of the pituitary gland on fertilization, embryonic development and serum steroid hormone levels of immature rats were studied to explore the cause of a low incidence of implantation of rats given a high dose of GTH.<BR>Both the incidence of rats with ova and the number of ova recovered from the uterus decreased with increasing doses of GTH and the lapse of time after mating. In the pituitary transplanted rats, 24 embryos or more per rat were recovered from the uterus 84 to 108 h after coitus. The fertility rates and embryonic development were normal in all groups with increase of serum progesterone levels. Estradio1-17β concentrations were significantly higher in 20 and 40 IU GTH-treated rats 12 to 60 h after mating than those in 5 IU PMSG•hCG-treated rats, whereas the levels in the pituitarytransplanted rats were similar to those in 5 IU GTH-treated rats.<BR>These results suggest that the incidence of implantation is closely related to serum estradio1-17β levels, and the low incidence of implantation in immature rats treated with high doses of GTH may be due to the embryonic loss from the uterus by accelerated transport. Furthermore the hormonal control through the pituitary gland should be important for a success of inducing superfecundation in immature rats.
日本繁殖生物学会の論文