Comments: A more recent study confirming androgen receptor decline in sexually exhausted rats. The study found receptors returning to normal by 72 hours, but full sexual potency takes 15 days to fully return. Other factors must be involved in sexual inhibition of sexual behavior for 15 days
Romano-Torres M, Phillips-Farfán BV, Chavira R, Rodríguez-Manzo G, Fernández-Guasti A.
Neuroendocrinology. 2007;85(1):16-26. Epub 2007 Jan 8.
Department of Pharmacobiology, Centro de Investigación y Estudios Avanzados, Mexico City, Mexico.
Recently we showed that 24 h after copulation to satiety, there is a reduction in androgen receptor density (ARd) in the medial preoptic area (MPOA) and in the ventromedial hypothalamic nucleus (VMH), but not in the bed nucleus of the stria terminalis (BST).
The present study was designed to analyze whether the ARd changes in these and other brain areas, such as the medial amygdala (MeA) and lateral septum, ventral part (LSV), were associated with changes in sexual behavior following sexual satiety.
Males rats were sacrificed 48 h, 72 h or 7 days after sexual satiety (4 h ad libitum copulation) to determine ARd by immunocytochemistry; additionally, testosterone serum levels were measured in independent groups sacrificed at the same intervals. In another experiment, males were tested for recovery of sexual behavior 48 h, 72 h or 7 days after sexual satiety. The results showed that 48 h after sexual satiety 30% of the males displayed a single ejaculation and the remaining 70% showed a complete inhibition of sexual behavior.
This reduction in sexual behavior was accompanied by an ARd decrease exclusively in the MPOA-medial part (MPOM). Seventy-two hours after sexual satiety there was a recovery of sexual activity accompanied by an increase in ARd to control levels in the MPOM and an overexpression of ARd in the LSV, BST, VMH and MeA.
Serum testosterone levels were unmodified during the post-satiety period. The results are discussed on the basis of the similarities and discrepancies between ARd in specific brain areas and male sexual behavior.