Androgenic Stimulation of Progesterone Production by Granulosa Cells from Preantral Ovarian Follicles: Furtherin VitroStudies Using Replicate Cell Cultures
The influence of testosterone (T) on progesterone (P) production by isolated rat ovarian granulosa cells was studied in vitro using a new replicate culture technique. Preantral granulosa cells from ovaries of estrogen-primed hypophysectomized immature female rats were cultured in the presence of graded concentrations of T, diethylstilbestrol (DES), cyproterone acetate (CPA), flutamide and the hydroxylated derivative of flutamide, Sch 16423 [.alpha.,.alpha.,.alpha.,-trifluoro-2-methyl-4''-nitro-m-lactotoluidide]. The accumulation of P in medium collected from granulosa cell cultures was measured by specific radioimmunoassay. Maximal P production by cultured granulosa cells was attained during the 2nd day of culture and declined markedly thereafter. The presence of 10-9, 10-8 or 10-7M T elicited increases in P production 2.4, 8 and 11 times that of controls, respectively, during the initial 48 h of culture. Each concentration of T elicited enhanced P production within the first 24 h of culture. Granulosa cells cultured in control medium for 2 days did not respond to 10-7M T during the subsequent 3 days. DES at a high concentration in the medium (10-5M) markedly suppressed the response to 10-9 and 10-8M T. At a lower concentration (10-9M) DES significantly enhanced the stimulatory effect of 10-9M T but did not alter the response to higher concentrations of T. Neither high nor low concentrations of DES influenced P production in response to 10-7M T. The stimulatory effects of T on P production were suppressed in the presence of a 100-fold molar excess of the anti-androgens, CPA or Sch 16423. Androgenic stimulation of P production by preantral granulosa cells is a specific receptor mediated event which is modulated by the presence of estrogen in vitro. Androgen-responsive P production may be a functional capacity which granulosa cells acquire at a very early stage of hormonal differentiation and may be of physiological consequence in the intraovarian control of follicular maturation in vivo.