Proliferative effect in vitro of follicle-stimulating hormone on the left ovary of the chick embryo.
The purpose of the present study was to evaluate the effect of human follicle-stimulating hormone (hFSH) on cellular proliferation in the chick embryo ovary. Left ovaries from 18-day-old chick embryos (Babcock B300) were dissociated by trypsin (0.25%) treatment. In some experiments, dissociated ovarian cells were further separated by a continuous metrizamide gradient (0-20%). Four cellular subpopulations were recovered from the density gradient: (a) typical steroidogenic cells (F1, density 1.026 g/ml), (b) primary oocytes (F2, 1.048 g/ml), (c) pregranulosa cells, and (d) poorly differentiated epithelial cells (both cellular types were found in F3, 1.059 g/ml, and F4, 1.071 g/ml). Samples (5 x 10(5) cells) of dissociated cells of the whole ovary and of the four cellular subpopulations obtained from the density gradient were cultured on polycarbonate membranes in a defined medium with 0.1 microCi of [3H]thymidine for 60 hr. When necessary, 17beta-estradiol, hFSH, recombinant human FSH, and hCG were added to the medium at the begining of the culture. The total number of cells and the incorporation of [3H]thymidine to the ovarian cell aggregate at the end of the culture increased when hFSH and recombinant hFSH (0.5 IU/ml) were added. No changes were produced with hCG (2.0 IU/ml) and 17beta-estradiol (200 ng/ml) treatments. The secretion of 17beta-estradiol by cultured ovarian cells was stimulated in the hFSH-, recombinant hFSH-, and hCG-treated groups. The dose-response curve to hFSH resulted in an ED50 of 0.03 IU/ml. In the temporal curve, the stimulatory effect of hFSH on the total number of cells and the [3H]thymidine incorporation were observed at 36 hr of culture and maintained up to 60 hr. The proliferative effect of hFSH measured as [3H]thymidine incorporation was observed only in the F4 fraction of the density gradient, which includes poorly differentiated epithelial cells and pregranulosa cells from the ovarian medulla and cortex, respectively. Present results demonstrate a dose-dependent stimulation of DNA synthesis by hFSH in the inmature ovary of the 18-day-old chick embryo. Either pregranulosa cells or poorly differentiated epithelial cells or both subpopulations would be the target cells for the proliferative effect of the gonadotropin.
Velázquez
P N
PN
Facultad de Medicina, Universidad Nacional Autónoma de México, México, DF 04510, Mexico.
Peralta
I
I
Pedernera
E
E
D000818:Animals; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D002642:Chick Embryo; D006063:Chorionic Gonadotropin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000032:analysis / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology*; D006801:Humans; D008854:Microscopy, Electron; D010053:Ovary / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D011994:Recombinant Proteins / Q000494:pharmacology; D013936:Thymidine / Q000378:metabolism; D013997:Time Factors; D014316:Tritium
D006063:Chorionic Gonadotropin; D011994:Recombinant Proteins; D014316:Tritium; D004958:Estradiol; D005640:Follicle Stimulating Hormone; D013936:Thymidine