Influence of gonadotrophins on early follicle cell development and early oocyte growth in the immature rat.
Ovaries of neonatal rats were transplanted on the day after birth into ovariectomized (high gonadotrophin levels) or ovariectomized-hypophysectomized adult female rats (extremely low gonadotrophin levels). Although transplantation caused a reduction of the number of growing follicles in all transplants, it did not seem to induce a clearly abnormal course of follicle development. After 15 days of development, the hormone-rich transplants contained a greater number of follicles larger than type 4 and a smaller number of oocytes with diameters less than 21 micrometers, than did the hormone-poor transplants. In the transplants with high hormone levels, the smallest follicles (types 2--3a) showed advanced transition of flattened into cuboidal follicle cells and oocyte growth. It is concluded that in these experimental conditions gonadotrophins, presumably especially FSH, seem to have a stimulatory effect on early follicle cell development and early oocyte growth.
D000818:Animals; D000831:Animals, Newborn; D002369:Castration; D002452:Cell Count; D005260:Female; D005640:Follicle Stimulating Hormone / Q000502:physiology; D006062:Gonadotropins / Q000502:physiology*; D007016:Hypophysectomy; D009865:Oocytes / Q000166:cytology / Q000254:growth & development*; D006080:Ovarian Follicle / Q000166:cytology / Q000254:growth & development*; D010053:Ovary / Q000637:transplantation; D010063:Ovum / Q000254:growth & development*; D051381:Rats; D011919:Rats, Inbred Strains
D006062:Gonadotropins; D005640:Follicle Stimulating Hormone