Effect of restraint stress on gonadal proopiomelanocortin peptides and the pituitary-testicular axis in rats
1990; Elsevier BV; Volume: 46; Issue: 22 Linguagem: Inglês
10.1016/0024-3205(90)90398-b
ISSN1879-0631
Autores Tópico(s)Sperm and Testicular Function
ResumoWe examined the effect of restraint on testicular interstitial fluid (TIF) concentrations of ACTH, β-endorphin-lipotropin (β-E-LI) and testosterone and correlated those changes with plasma concentrations of ACTH, β-E-LI, corticosterone, LH and testosterone in adult rats. Animals were subjected to 1, 2, or 3 h of restraint and were killed immediately following the stress period. Plasma values of ACTH and β-E-LI were elevated above control values after 1 and 2 h, but not after 3 h of restraint. Plasma corticosterone showed a similar response to restraint except that concentrations were also elevated after 3 h. Plasma testosterone concentrations were elevated after 1 h of restraint, but after 3 h of restraint had fallen below control values. Restraint reduced plasma testosterone concentrations without altering plasma LH concentrations. The decline in plasma testosterone during restraint was associated with a parallel decrease in testosterone in the TIF. Concentrations of ACTH and β-E-LI were 6- and 3-fold greater in TIF than in the plasma. While 1 or 2 h of restraint did not affect ACTH and β-E-LI in TIF, values of these hormones were elevated in rats exposed to 3 h of restraint. These data, coupled with recent reports that testicular proopiomelanocortin (POMC)-derived peptides may modulate testicular steroidogenesis, suggest that these factors may play an autocrine or paracrine role in mediating stressor-induced changes in testicular function.
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