Prostate response to prolactin in sexually active male rats

Abstract

Background: The prostate is a key gland in the sexual physiology of male mammals. Its sensitivity to steroid hormones is widely known, but its response to prolactin is still poorly known. Previous studies have shown a correlation between sexual behaviour, prolactin release and prostate physiology. Thus, here we used the sexual behaviour of male rats as a model for studying this correlation. Hence, we developed experimental paradigms to determine the influence of prolactin on sexual behaviour and prostate organization of male rats.

Correlation of prolactin levels and PRL-receptor expression with Stat and Mapk cell signaling in the prostate of long-term sexually active rats

“…As we have previously shown [1], PRL is one of the several hormones that stimulate this gland, and it has now been found that the stimulation is highly correlated with the sexual life of the subject. In male rats with a single sexual encounter, the fluctuation of serum PRL shows a transient increase, suggesting a long refractory period that makes the system controlling the release of PRL unresponsive to further mating stimuli [1]. Now, in this work we found that subjects engaged in continued sexual behavior over longer periods of time showed different serum PRL profiles, such that PRL levels were constantly elevated during mating.…”

“…Thus, the periodic execution of copulation during the sexual life of the subject is influenced by the constant elevated levels of serum PRL. However, serum PRL levels differed, so that in the case of males beginning their sexual life, the transient increase in serum PRL could reach up to 80 ng/ml [1], whereas subjects engaged in sexual behavior showed sustained elevation of serum PRL up to 30 ng/ml. Thus, periodic sexual behavior seems to modify the neuroendocrine circuit underlying PRL release.…”

“…e l s e v i e r . c o m / l o c a t e / p h b [1]. Thus, in sexually active males PRL plays a significant role in ensuring that the prostate produces an appropriate semen content for reproduction.…”

“…Males were cannulated for blood collection as previously described [1]. Selected subjects after the first training session were anesthetized with sodium pentobarbital (Smith Kline Mexico; 30 mg/kg bw, i.p.…”

“…It shows a daily basal level with two peaks at lightdark-light transitions [1], which serves among other things to potentiate the effect of androgens on sexual accessory glands and increase luteinizing hormone receptor levels in Leydig cells, which in turn increases testosterone synthesis [2]. Thus, although these are some functions of PRL, we have shown that PRL by itself is also important for other prostate functions, where it controls zinc uptake, citrate synthesis, and the expression of androgen receptors and cathepsin D [1,3]. Although basal levels of PRL are extremely important for maintenance of the prostate, there are some behavioral situations that produce a significant increase in serum PRL levels.…”