Sex steroids modulate prolactin action in spontaneously luteinizing porcine granulosa cells in vitro.
Prolactin (20-1000 ng/ml) stimulated progesterone secretion in monolayer cultures of granulosa cells isolated from mature (greater than 8 mm) porcine follicles. The action of 17 beta-estradiol alone and the interaction between estradiol and prolactin in controlling steroidogenesis were critically dependent upon the duration of hormone treatment. Acute administration (within 36 h) of 17 beta-estradiol, but not 17 alpha-estradiol, suppressed both spontaneous and prolactin-stimulated progesterone production. Continuation of estrogen treatment beyond 48 h markedly increased progesterone secretion per cell and with prolactin produced synergistic enhancement of progesterone accumulation. However, 5 alpha-dihydrotestosterone also significantly augmented progesterone production after both acute and prolonged administration. The steroidogenic effect of prolactin was greater in the presence of 5 alpha-dihydrotestosterone, but did not elicit true synergism. Measurements of sex-steroids levels in porcine follicular fluids indicated that estrogen concentrations that were biologically active in vitro are similar to those attained in vivo. These observations suggest a major role for sex-steroid hormones both in the control of basal steroidogenesis and in the modulation of prolactin action in mature spontaneously luteinizing granulosa cells.
D000735:Androstenedione / Q000494:pharmacology*; D000818:Animals; D013196:Dihydrotestosterone / Q000494:pharmacology*; D004958:Estradiol / Q000494:pharmacology*; D004970:Estrone / Q000494:pharmacology*; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D006080:Ovarian Follicle / Q000502:physiology; D011374:Progesterone / Q000378:metabolism*; D011388:Prolactin / Q000494:pharmacology*; D013552:Swine; D013739:Testosterone / Q000494:pharmacology*
D013196:Dihydrotestosterone; D004970:Estrone; D013739:Testosterone; D000735:Androstenedione; D011374:Progesterone; D004958:Estradiol; D011388:Prolactin