Prolactin and Male Fertility: The Long and Short Feedback Regulation

Abstract

In the last 20 years, a pituitary-hypothalamus tissue culture system with intact neural and portal connections has been developed in our lab and used to understand the feedback mechanisms that regulate the secretions of adenohypophyseal hormones and fertility of male rats. In the last decade, several in vivo rat models have also been developed in our lab with a view to substantiate the in vitro findings, in order to delineate the role of pituitary hormones in the regulation of fertility of male rats. These studies have relied on both surgical and pharmacological interventions to modulate the secretions of gonadotropins and testosterone. The interrelationship between the circadian release of reproductive hormones has also been ascertained in normal men. Our studies suggest that testosterone regulates the secretion of prolactin through a long feedback mechanism, which appears to have been conserved from rats to humans. These studies have filled in a major lacuna pertaining to the role of prolactin in male reproductive physiology by demonstrating the interdependence between testosterone and prolactin. Systemic levels of prolactin play a deterministic role in the mechanism of chromatin condensation during spermiogenesis.

Exposure to bisphenol-A and reproductive hormones among male adults

“…Moreover, reverse causation is always a potential concern for this type of studies. However, high PRL would be expected to lead to lower BPA level (Gill-Sharma, 2009;Takeuchi et al, 2006), an opposite relation to what we observed. Thus, our results are unlikely as a result of reverse causation.…”

Effects of psychological stress on male fertility

“…95 Although prolactin has no specific target organ in men, it seems to have a number of nonspecific actions, including control of testosterone secretion 96 and control of sexual behaviour and activity. 97 Expression of prolactin receptors on the choroid plexuses and the hypothalamus suggests a latent role for prolactin in the regulation of male fertility.…”

Experimental Study for the Effect of Methyl Rednisolone on the Sexual Hormones Levels

“…Results concerning FSH hormone indicate the increase of the hormone level in blood sera of groups treated with high concentrations of the drug in comparison with may be attributed to the glucocorticoid drugs which reduce the hormone batches which release hormone GnRH secreted from hypothalamus gland [21].…”

“…regulated and have a role One of the factors that deter creating of Prolactin creating testosterone ; then these cells deter Prolactin while Estrogen hormone is considered a Prolactin stimulating agent . Relation between Prolactin and Testosterone is almost an inverse relationship , as the increase in Prolactin level is associated with the decrease of Testosterone in mature males [21].…”