REPEATED INTERRUPTIONS OF THE TESTICULAR BLOOD-FLOW DO NOT HAVE LONG-TERM EFFECTS ON SPERMATOGENESIS IN THE RAM

The effect of repeated interruptions of the testicular blood flow on s permatogenesis was studied in mature Texel rams. Reversible interrupti on of the blood flow was achieved by an inflatable occluder, placed ar ound the testicular artery at the level of the spermatic cord. In eigh t 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. Ni ne weeks after the last blood flow interruption spermatogenesis was ev aluated in histological sections of the testes. Both after six and nin e blood flow interruptions a qualitatively complete epithelium was fou nd 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 P releptotene Spermatocytes. After six occlusions the numbers of all cel l types were at or even slightly above control levels. These results s how that repeated periods of ischaemia for 1 h do not result in conspi cious long-term damage to spermatogenesis.