ABSTRACT
This study demonstrated that acute immobilization stress induced suppression in testosterone and elevation in cortisol levels in plasma of albino rats. The rise in cortisol is partially responsible for the declining in the testosterone concentrations. High serum level of glucocorticoids impaired directly the testicular function, decreased the sensitivity of pituitary gland to LHRH and reduced the hypothalamic release of LHRH. On the other hand, chronic immobilization stress, noisy test and harmony sounds induced a decrease in both testosterone and cortisol plasma levels. This indicated that other mechanisms were implicated in the suppression of testosterone level included the inhibition of the hypothalamic pituitary gonadal axis by increased prolactin secretion and the release of endogenous opioid peptides