Two in vivo models for studying the effects of temperature stress on adult testicular lipids and lipid metabolism

AYUZA-ARESTI, P. L.; ORESTI, G. M.; FURLAND N. E.; AVELDAÑO, M. I.

Buenos Aires

Congreso; II Reunión Científica Regional I Congreso Nacional de la Asociación Argentina de Ciencia y Tecnología de Animales de Laboratorio; 2007

Asociación Argentina de Ciencia y Tecnología de Animales de Laboratorio- Soc. Arg. de Medicina Verterinaria

Cryptorchidism and mild testicular hyperthermia are temperature-related stress factors that induce selective apoptotic death of germ cells in the testis. Adult rat testis exposed to abdominal temperature (38ºC) display, after a few days, a marked depletion of germinal cells, and drastic changes in testicular size, histology, and lipid content and composition. A less harmful animal model of temperature-induced stress is mild, transient hyperthermia. In this work we compared the time course of lipid changes in cryptorchidism and in a heat stress model that consisted in short periods (15 min) of in vivo exposure of testis to relative hyperthermia (43ºC) applied once a day during 5 consecutive days. Both models induced progressive and selective depletion of spermatocytes and spermatids. Ten days of criptorchidism and 3 weeks after the repeated episodes of mild hyperthermia, practically no germ cells remained in the seminiferous tubules, which consisted mainly of Sertoli cells and spermatogonia. This was accompanied by dramatic reductions of phospholipids and accumulation of neutral lipids, clearly observed in compositional and metabolic studies. With the latter model it was possible to observe a slow (several weeks) but positive trend of reversion of the temperature-related cellular and biochemical changes. We conclude that mild testicular hyperthermia is an excellent research model of spermatogenic arrest. It may help to pinpoint experimental factors that promote the recovery of normal fertility after temperature-induced stress.