Localization of gamma-butyrobetaine hydroxylase in the rat testis.

The activity of gamma-butyrobetaine hydroxylase in testes is comparable on a protein basis to the amount of activity found in liver and accounts for a significant amount of the total activity found in the rat. The enzyme is localized to the seminiferous tubules of the testes. In attempting to further localize this enzyme, activity remained the same when reported on a protein basis in cryptorchid testes as compared to controls, and activity was found in bovine sperm cells obtained from the caput epididymis. These results are consistent with the localization of this enzyme in both the Sertoli cells and the germ cells.