Endocrinology, Vol 114, 1550-1557, Copyright © 1984 by Endocrine Society

ARTICLES

Estrogen stimulates prolactin gene transcription by a mechanism independent of pituitary protein synthesis

JD Shull and J Gorski

We have used an in vitro nuclear transcription system to investigate the mechanisms through which 17 beta-estradiol regulates PRL gene expression in the rat pituitary. A single injection of this estrogen stimulated the rate of PRL RNA synthesis in nuclei isolated from male rats within 30 min of treatment, and this stimulated rate of PRL RNA synthesis was observed for at least 48 h after injection. In contrast, estrogen treatment had little effect on the rate of GH RNA synthesis. Cycloheximide, at a dose sufficient to inhibit pituitary protein synthesis by greater than 80%, did not block this estradiol-mediated stimulation of PRL RNA synthesis through at least the first 8 h after hormone treatment. Estradiol treatment also resulted in a rapid transformation of the pituitary estrogen receptors from the cytosolic to the nuclear form. However, the level of receptor in the nuclear form peaked within 1 h and had returned to near the control value within 6 h of hormone injection. These studies suggest that 17 beta-estradiol regulates PRL gene transcription through a mechanism independent of pituitary protein synthesis. In addition, the rates of PRL RNA synthesis over the time course examined were not correlated with the percentage of the pituitary estrogen receptor population existing in the nuclear form.

This article has been cited by other articles:

				J. J. Watters, T.-Y. Chun, Y.-N. Kim, P. J. Bertics, and J. Gorski Estrogen Modulation of Prolactin Gene Expression Requires an Intact Mitogen-Activated Protein Kinase Signal Transduction Pathway in Cultured Rat Pituitary Cells Mol. Endocrinol., November 1, 2000; 14(11): 1872 - 1881. [Abstract] [Full Text]

				M. E. Freeman, B. Kanyicska, A. Lerant, and G. Nagy Prolactin: Structure, Function, and Regulation of Secretion Physiol Rev, October 1, 2000; 80(4): 1523 - 1631. [Abstract] [Full Text] [PDF]

				C. Ying and D.-H. Lin Estrogen-modulated Estrogen Receptor{middle dot}Pit-1 Protein Complex Formation and Prolactin Gene Activation Require Novel Protein Synthesis J. Biol. Chem., May 12, 2000; 275(20): 15407 - 15412. [Abstract] [Full Text] [PDF]

				D. L. Allen, N. A. Mitchner, T. E. Uveges, K. P. Nephew, S. Khan, and N. B. Jonathan Cell-Specific Induction of c-fos Expression in the Pituitary Gland by Estrogen Endocrinology, May 1, 1997; 138(5): 2128 - 2135. [Abstract] [Full Text]