A study of warm testicular ischaemia and paternity in rats

The effect of testicular ischaemia on fertility as assessed by paternity rate was studied in seven groups of male Sprague-Dawley pubertal rats. Transient unilateral occlusion of the testicular artery and venous outflow was performed for 30, 60, 90, and 120 min using non-crushing microvascular clamps in groups 1–4 (n = 6). Group 5 (n = 12, Fowler-Stephens) had division of both the testicular artery and vein, whereas group 6 (n = 12, Refluo) had division of the testicular artery only. Group 7 (n = 6) consisted of controls upon whom a sham operation was performed. Testicular biopsy 6 weeks after transient testicular ischaemia of 30, 60, and 90 min showed tubular atrophy in 20%–33% of the testes. Ischaemia of 120 min led to tubular atrophy in 84% of testes. Division of only the testicular artery caused tubular atrophy in 58% of testes. Division of both testicular artery and venous outflow was associated with total tubular destruction and necrosis in 78% of testes and 22% had variable tubular atrophy. A paternity rate of 50%–80% was noted in groups 1–4 following transient unilateral testicular ischaemia and contralateral vasectomy. This compared well with the expected 75% paternity rate for a control rat population. Chronic ischaemia (group 5) together with testicular venous interruption was associated with observably lower fertility and a paternity rate of 18%. However, when venous outflow was preserved (group 6), chronic ischaemia after testicular artery division did not affect the paternity rate (50%) significantly. Offprint requests to: A. Bianchi