The effect of estrogens and progestins on monkey prolactin synthesis.
Dispersed monkey pituitary cells were cultured on extracellular matrix and in serum-free medium for up to 1 month, with medium changes every other day. The cells were treated with ethanol vehicle or 10 nM 17 beta-estradiol (E2 beta), 17 alpha-estradiol (E2 alpha), progesterone (P4), pregnenalone (P5), 17 alpha-hydroxyprogesterone (17OH P4), and E2 beta plus P4. Immunoreactive PRL (IR-PRL) levels in 48 h medium samples were first determined with a homologous human PRL RIA and then with a heterologous monkey PRL RIA. On the last day of culture, the cells were incubated with [35S]methionine for 4 h, and 35S-labeled PRL in the medium and cells was determined and compared to 4 h IR-PRL. Differences between control and treated groups in 48 h IR-PRL were greater with the heterologous monkey RIA. E2 beta, E2 alpha, and E2 beta plus P4 significantly elevated IR-PRL in 48 h medium samples an average of 73%, as determined with the monkey RIA. P4, P5, or 17OH P4 had no effect on IR-PRL in 48 h medium samples. Secreted and intracellular [35S]PRL were consistently elevated by E2 beta and E2 beta plus P4, but less consistently elevated by E2 alpha. P4, P5, or 17OH P4 had little effect on [35S]PRL in medium or cells. IR-PRL in the 4 h medium sample and cells generally paralleled [35S]PRL, although E2 alpha caused a more consistent elevation in IR-PRL than in [35S]PRL. In summary, E2 beta and E2 alpha directly stimulate PRL synthesis by monkey pituitary cells on extracellular matrix in long term serum-free culture. Nanomolar levels of progestins have little direct effect on PRL synthesis, nor does 10 nM P4 block the stimulatory effect of E2 beta.
D019326:17-alpha-Hydroxyprogesterone; D000818:Animals; D002478:Cells, Cultured; D004958:Estradiol / Q000494:pharmacology; D004967:Estrogens / Q000494:pharmacology*; D005260:Female; D006908:Hydroxyprogesterones / Q000494:pharmacology; D008253:Macaca mulatta; D008297:Male; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism*; D011280:Pregnanolone / Q000494:pharmacology; D011374:Progesterone / Q000494:pharmacology; D011372:Progestins / Q000494:pharmacology*; D011388:Prolactin / Q000096:biosynthesis*; D011863:Radioimmunoassay
D004967:Estrogens; D006908:Hydroxyprogesterones; D011372:Progestins; D011374:Progesterone; D004958:Estradiol; D019326:17-alpha-Hydroxyprogesterone; D011388:Prolactin; D011280:Pregnanolone