A quantitative study of the effect of heat on germinal epithelium of rat testes

Abstract A quantitative study of changes in the germinal epithelium of rat testes exposed to 43°C for 15 minutes was performed. Testicular tissue was studied at intervals of 2, 4, 6, 8 and 26 days after exposure to heat. The frequency distribution of the various stages of spermatogenesis, the resting spermatocytes, spermatogonia and Sertoli cells were not affected by the exposure to heat. On the other hand, primary spermatocytes in stage IX (leptotene), to and including dividing spermatocytes in stage XIV, were injured, excepting for pachytene spermatocytes in stages V and VI of spermatogenesis. The spermatids were affected by heat only in step 1 and the early part of step 2 of spermiogenesis. Those beyond step 2 continued to mature and form adult spermatozoa. The data indicate that heat produces selective damage to the germinal epithelium affecting only specific types of germinal epithelium cells.