Modulation of prolactin receptors in the male rat
Prasad, M.S.; Adiga, P.R.
Indian Journal of Experimental Biology 17(11): 1166-1170
1979
ISSN/ISBN: 0019-5189 PMID: 233009 Document Number: 145280
Studies on the ontogeny of prolactin [PRL] receptors in the various tissues of the male rat suggested that the tissues (except testis) in general acquire greater capacity to interact with PRL around 40 days of age. Castration drastically reduced the number of PRL receptors in the prostate without significantly altering their levels in the liver and the kidney. Administration of estradiol-17.beta. to the castrated rats increased 125I-labeled PRL binding to the membranes from the liver and the kidney, suggesting that the steroid hormones profoundly influence PRL receptors in these tissues. The testis displayed greater capacity to bind the labeled hormone around 20 days of age. Serum PRL exhibited peak levels around 40 days of age. The apparent lack of correlation between the serum PRL and testicular PRL receptor contents revealed the absence of any marked receptor autoregulation in this tissue during puberty in the rat. In support of this, neutralization of the endogenous PRL for short duration with specific anti-rat PRL serum failed to significantly alter PRL binding to the testicular membranes thereby suggesting that deprivation of PRL for short duration did not significantly affect tissue receptor content of the hormone.