Repeated interruptions of the testicular blood flow do not have long-term effects on spermatogenesis in the ram

Summary. The effect of repeated interruptions of the testicular blood flow on spermatogenesis was studied in mature Texel rams. Reversible interruption of the blood flow was achieved by an inflatable occluder, placed around the testicular artery at the level of the spermatic cord. In eight testes the blood flow was successfully interrupted six times for 1 h within 3 weeks and in 14 testes nine times for 1 h within 3 weeks. Nine weeks after the last blood flow interruption spermatogenesis was evaluated in histological sections of the testes. Both after six and nine blood flow interruptions a qualitatively complete epithelium was found in at least 90% of the seminiferous tubules. Cell counts in stages VII and VIII of the spermatogenic cycle revealed a slight decrease of spermatocytes and spermatids in the tubules with a complete epithelium after nine occlusions, which was only statistically significant for Preleptotene Spermatocytes. After six occlusions the numbers of all cell types were at or even slightly above control levels. These results show that repeated periods of ischaemia for 1 h do not result in conspicious long-term damage to spermatogenesis.