EFFECT OF LOCAL HEATING ON BLOOD FLOW AND METABOLISM IN THE TESTIS OF THE CONSCIOUS RAM

Abstract

The metabolic effects of elevated temperature on the testes of conscious rams have been investigated. Locally heating the testes above 39\s=deg\C for 2 to 2\ m=1/ 2\ hr caused moderate or severe seminal degenera-tion. Blood flow through the testes was not consistently changed by the heating applied. More oxygen was removed from a unit volume of the blood passing through the testes when testicular temperatures were higher than 36 \m=.\3to 37\ m=. \ 2\ s=deg\ C, than at control temperatures. The oxygen content of the blood in the spermatic veins fell to 2\m=.\7to 4\m=.\9ml 02/100 ml during heating, and oxygen uptake by the testis and epididymis increased by about 70%. In most testes glucose uptake was increased by heating; there was no consistent change in lactate production. It was concluded that heat sufficient to cause spermatogenic damage results in hypoxia in the testis but does not consistently alter the blood flow or the supply of glucose or the important role of glucose in testicular metabolism.