Effect of immobilization stress on testosterone and inhibin in male rats.

Adult male Wistar rats were subjected to acute and chronic immobilization stress. Changes in plasma levels of LH, FSH and testosterone and in the content of testicular inhibin and testosterone were studied. Plasma LH levels decreased significantly in response to both acute and chronic stress. Significant decreases in plasma testosterone content were also observed after chronic stress. In contrast, plasma FSH and testicular bioassayable inhibin content did not change after acute or chronic stress. These findings indicate that in male rats immobilization stress induced a dissociation in LH and FSH responses, and decreased testosterone while inhibin remained unaffected.