Effects of prolactin on estrogen, cAMP and oxytocin secretion by porcine granulosa cells in vitro.
Granulosa cells were isolated from ovaries (without pre-ovulatory follicles or corpora lutea) of cycling gilts slaughtered at 8 months of age. They were cultured in the presence or absence of exogenous porcine prolactin (1, 10, 1,000, 10,000, or 100,000 pmol/ml medium). The secretion of estrogen, cAMP and oxytocin into the incubation medium was analysed by radioimmunoassay. It was found that prolactin (10, 1,000, 10,000 and 100,000 pmol/ml) inhibited estrogen secretion (p < 0.001) and stimulated cAMP output (p < 0.001, p < 0.001, not significant, and p < 0.01, respectively). Small doses of prolactin (1 and 10 pmol/ml) decreased (p < 0.001, p < 0.05), whilst high doses (1,000, 10,000 and 100,000 pmol/ml) increased (p < 0.001) oxytocin secretion by granulosa cell culture. The data suggest a direct action of prolactin on porcine ovarian cyclic nucleotides, steroid and nonapeptide hormone release.
Sirotkin
A V
AV
Research Institute of Animal Production, Nitra, Slovakia.
Nitray
J
J
D000818:Animals; D002478:Cells, Cultured; D000242:Cyclic AMP / Q000378:metabolism*; D004967:Estrogens / Q000378:metabolism*; D005260:Female; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism*; D007700:Kinetics; D010121:Oxytocin / Q000378:metabolism*; D011388:Prolactin / Q000008:administration & dosage / Q000494:pharmacology*; D013552:Swine / Q000502:physiology*
D004967:Estrogens; D010121:Oxytocin; D011388:Prolactin; D000242:Cyclic AMP