AJP - Endocrinology and Metabolism, Vol 240, Issue 6 602-E608, Copyright © 1981 by American Physiological Society
Sensitivity of rat adenohypophyseal cells to estradiol and LHRH during long-term culture
L. Lagace, F. Labrie, T. Antakly and G. Pelletier
To determine possible effects of the time in culture on the responsiveness
of the different pituitary cell types to estrogens, rat anterior pituitary
cells were incubated up to 20 days in the presence or absence of 10 nM 17
beta-estradiol. Whereas spontaneous luteinizing hormone (LH) and
thyroid-stimulating hormone (TSH) release decreased by 85-90%,
follicle-stimulating hormone (FSH) and prolactin accumulation in medium
were only 50% decreased after 20 days in culture, thus suggesting that the
secretion of FSH and prolactin is less dependent on extrinsic stimulatory
factors. Estradiol increased spontaneous LH release and its responsiveness
to luteinizing hormone-releasing hormone (LH-RH) up to day 16 in culture,
whereas the stimulatory effect of the estrogen on FSH secretion was
significant only up to day 6. The stimulatory effect of estradiol on basal
TSH release was seen up to day 8 in culture, whereas that on spontaneous
prolactin release increased progressively after day 8 in culture up to the
last time interval studied (20 days). As revealed by immunocytochemistry,
the stimulatory effect of estradiol was not due to changes of cell growth.
