[Proteins of mouse spermatogenic cells. I. Enzymatic activity and electrophoretic spectrum].

The proteins characteristic of the whole period of differentiation constitute the main bulk of soluble proteins in the spermatogenic cells. Their content and enzymatic activity are subject to marked changes during spermatogenesis. The activity of glycolysis and pentose cycle enzymes is jointly changed; the fluctuations of enzymes of pyruvate oxidation and Krebs-cycle are in antiphase. Sorbitol dehydrogenase suffers marked activation in the late spermiogenesis. This process is facultative and is not expressed in the cells of young animals. It is suggested that the level of sorbitol dehydrogenase may serve as an index of biochemical maturity of late spermatids.