Seasonal response of carp (Cyprinus Carpio) ovarian cells to stimulation by various hormones as measured by steroid secretion

Objective. To study seasonal variation of steroid secretion by dispersed carp ovarian follicular cells as influenced by carp pituitary homogenate (CPH), human chorionic gonadotropin (hCG) or 17α, 20β-dihydroxy-4-pregnen-3-one (17α,20βOH-P). Methods. Carp ovaries were collected each month throughout the year from January to Decem-ber. The cells of ovarian follicles were dispersed by trypsin treatment and cultivated as monolayers. Control cultures were grown in medium M199 alone. Media for experimental cultures were sup-plemented either with CPH, hCG or (17α,20βOH-P). The direct effect of these three factors on progesterone (P 4), androgens and estradiol (