Distribution pattern of testicular sulphydryloxidase immuno-activity in the djungarian hamster (Phodopus sungorus) during photoperiodically induced involution and recrudescence.

The distribution pattern of testicular sulphydryloxidase (SOx) immuno-activity was investigated in the djungarian hamster during photoperiodically induced testicular involution and recrudescence. SOx immuno-activity, indicating functional integrity of labelled cells, did not change in pachytene spermatocytes and spermatids as long as these cells were present in the seminiferous epithelium. Its disappearance coincided with the degeneration of spermatocytes in phases IV and V of involution and reappeared during recrudescence, when the first spermatogenic wave had reached the pachytene stage. In tubules at phase VI of involution (showing maximal regression), the apical cytoplasm of Sertoli cells showed immuno-activity. This immuno-activity disappeared during recrudescence prior to the differentiation of pachytene spermatocytes. Changes in SOx immuno-activity resembled those of lactate dehydrogenase-X (LDH-X) in photo-inhibited testes or during puberty, indicating a close functional relationship which still remains to be elucidated. The data suggest that the hamster exposed to different photoperiods can be used as a suitable model to study the relationship between testicular morphology and function in different states of gonadal activity.