Incorporation of l-lysine-U-C14 into proteins of cryptorchid testis slices

Abstract

The incorporation of l-lysine-U-C14 into protein of slices of experimentally induced cryptorchid testes of the rat has been studied at various time periods ranging from 4 to 40 days after abdominal transplantation. Comparisons of protein labeling from radioactive lysine into slices of adult scrotal testes, immature testes, and an interstitial-cell testicular tumor of the mouse have also been carried out. In addition, the effects of temperature and of exogenous glucose on protein labeling of these tissues have been investigated. The data obtained indicate that the incorporation of labeled lysine into protein of slices of cryptorchid testes is markedly greater than that observed for slices of scrotal testes obtained from the same animal. It is suggested that of the various cell types found in the rat testis, the spermatogonia and primary spermatocytes demonstrate the highest degree of protein labeling from radioactive lysine and that the enzymatic systems involved in the incorporation of radioactive lysine into protein of the spermatids display the most susceptibility to elevated temperatures and the greatest sensitivity to the addition of exogenous glucose.