Changes in 3beta-HSD, 11beta-HSD type 1, and apoptotic proteins in rat testis induced by psychosocial stress

Stress in socially subordinate male rats, associated with aggressive attacks by dominant males, was studied in a group-housing context called visible burrow system (VBS). These data show that subordinate males have reduced serum testosterone and higher corticosterone relative to dominant and singly housed control males (Hardy et al. 2002: Biol. Reprod., 67, 1750–1755). The aim of this report is to describe the morphological and histochemical changes in the testes of dominant and subordinate males on day 4, 7, and 14 of a 14-day housing period in the VBS. Testes from 25 control, 39 subordinate and 26 dominant rats were processed. Results: Immunohistochemical reaction for type 1 11βHSD, a glucocorticoid-metabolizing enzyme, showed strongest intensity in the Leydig cells of dominant animals compared with control and subordinates. Also the intensity of enzyme reaction of 11βHSD in subordinate rats was lower relative to control; dominant rats had a stronger enzyme reaction than controls and subordinates. The staining intensity for 3βHSD, a testosterone-synthesizing enzyme, in the cytoplasm of Leydig cells was consistently higher in dominant males compared to subordinates. The difference between dominant and subordinates was detectable by 4 days of VBS housing and was maintained through 14 days. A distinct immune reaction for BAK was present in elongated spermatids of controls and dominants; the reaction intensity decreased in the subordinates. The Bcl2 reaction in the elongated spermatids during the stages IX to XI of spermatogenesis in subordinates was stronger than in controls and in dominants. There was no significant difference in the frequency of stages of spermatogenesis of these three groups. To conclude, Leydig cells of socially dominant rats contain more 3β- and 11βHSD enzyme activity compared to thier psychosocially stressed subordinates. This supports the hypothesized protective role of oxidative activity of 11βHSD in maintaining androgen production in Leydig cells by inactivating glucocorticoids.