Enzyme activities in cynomolgus monkey and mouse spermatozoa evaluated histochemically during epididymal maturation

Activities of dehydrogenases, phosphorylases, and hydrolases were investigated histochemically in situ comparatively in monkey (Macaca fascicularis), and mouse testicular and epididymal spermatozoa. Longitudinal sections of the whole mouse epididymis also were processed to evaluate the progressive changes along the duct. Numerous common enzymatic activities were found in spermatozoa of both species, particularly the dehydrogenases in the midpiece. However, there were specific differences concerning the occurrence, the distribution, and the intensity of several reactions. The activities acquired in the testis persisted or increased in the epididymis, in which some new enzyme activities arose. The main events occurred at the proximal part of the duct.