Deoxyribonucleic acid cytophometry on rat ovarian follicles kept in organ culture: the effects of gonadotropins and plasma from normal, hypergonadotropic menopausal, and hypogonadotropic women.

Pituitary FSH as well as urinary FSH were found to be potent stimulators of in vitro granulosa cell DNA synthesis in Wistar rat ovarian segments kept in organ culture. Optimal responses were reached at the highest concentration used (pituitary FSH, 5 mU/mL: urinary FSH, 50 mU/mL). hCG also appeared to be a potent stimulator (optimal response, 5 mU/mL). LH showed no stimulating effect, but the hormone had a potentiating effect on FSH-induced DNA synthesis. Plasma samples of five normally menstruating women obtained at different stages of the follicular phase were also added to the rat ovarian culture system. All samples stimulated DNA synthesis, but the plasma samples obtained in the late follicular phase showed stronger growth responses, reaching optimal values at lower concentrations compared to the potency of plasma obtained in the early follicular phase (10(-3)-10(-5) vs. 10(-2)-10(-3) mL, respectively). The strong bioeffect of late follicular phase plasma could partly be explained by the potentiating effects of plasma LH on FSH-induced DNA synthesis. When plasma samples of five hypergonadotropic amenorrheic women were added to the culture system, 4 stimulated DNA synthesis moderately, with an optimal growth response at plasma concentrations of 10(-4)-10(-3) mL. When 10 plasma samples of hypogonadotropic amenorrheic women were added to the culture system, 8 had no effect on DNA synthesis, and clear discrepancies were evident between the low to absent ovarian growth potential of the plasma and the practically normal immunoreactive plasma FSH measured by RIA and immunoradiometric assay. These discrepancies may be the effect of nonimmune or immune factors interfering with FSH-induced growth or the effect of molecular changes in the FSH molecule (isoforms).