Testicular capillary blood flow in the impubertal lamb and the ram during the breeding and non-breeding seasons.

The testicular capillary blood flow was measured by the 133Xenon clearance technique in the Ile-de-France lambs and rams in Spring and Autumn. Anaesthetized animals were maintained in the supine position and 133Xe was injected into the testicle through the scrotal skin. In the adult, the blood-flow (ml/min./100 g) depended upon the season: 8.3 +/- 1.0 vs 12.7 +/- 0.7 in May and October (P less than 0.001). In the impubertal lamb (50 days old) regardless of the period of the year, the blood flow was the same as in the adult in the breeding season (11.4 +/- 1.2 vs 12.7 +/- 0.7). In prepubertal lambs (120 days old) the rapid increase in testicular weight was not correlated with an increase in the blood flow (9.4 +/- 0.7).