AJP - Endocrinology and Metabolism, Vol 250, Issue 1 103-E105, Copyright © 1986 by American Physiological Society
Estradiol induces a shift in cultured cells that release prolactin or growth hormone
F. R. Boockfor, J. P. Hoeffler and L. S. Frawley
The process by which estradiol induces an increase in the percentage of
prolactin cells in the rat pituitary requires clarification. In this study
the effect of estradiol treatment on growth hormone and prolactin cells in
monolayer cultures of male rat pituitaries was assessed by use of reverse
hemolytic plaque assays. Treatment of cultures with 17 beta-estradiol (10
nM) for 6 days elevated significantly (P less than 0.01) the percentage of
all cells in culture that released prolactin without affecting the
percentage of growth hormone secretors. However, by sequentially assaying
single cells for growth hormone and prolactin, we found that estradiol
caused a marked increase (P less than 0.01) in the proportion of individual
cells that released both growth hormone and prolactin and a commensurate
decrease in the proportion that released growth hormone alone. These
results demonstrate that estradiol acts directly on cultures of male
pituitary cells to shift the proportions of cells that released growth
hormone, prolactin, or both hormones and indicate that estradiol may
convert cells that release only growth hormone to those that release both
growth hormone and prolactin.
