Influence of FSH on the developing ovary in the chick embryo

Pituitary gonadotrophins, especially FSH, are essential for the growth, development and maintenance of ovarian follicles after birth; however the effects, from increased or decreased secretion of these hormones, on the development of foetal gonads need further investigation. In this paper we report the histological changes of the ovaries, observed in chick embryos treated with FSH. Forty six female Leghorn chick embryos, obtained from three successive incubations, were used. Each incubation took place at a constant temperature of 37.5 ± 2° C for 19 days. 20 embryos were used as controls, while in the other 26 embryos an intraembryonic injection of FSH was given on the 12th day of incubation in a dose of 100 μg of NIH-FSH-S2 Ovine (solution of 200 μg FSH/ml normal saline). All embryos were killed on the 19th day of incubation and the ovaries were removed, fixed in a solution of 10%