Histochemical localization of glycolytic enzymes, alcohol and secondary-alcohol dehydrogenases in the testes of buffaloes, goats and rams

Abstract

SUMMARYGlyceraldehyde-3-phosphate dehydrogenase (G-3-PDH), αglycerophosphate dehydrogenase (αGPDH), lactate dehydrogenase (LDH), alcohol dehydrogenase (ADH) and secondary-alcohol dehydrogenase (SADH) were histochemically located in the testes of buffaloes, goats and rams. Two forms of αGPDH were observed: (i) NAD-dependent or cytoplasmic αglycero-phosphate dehydrogenase (αGPDHC) and (ii) NAD-independent or mitochondrial αglycerophosphate dehydrogenase (α GPDHM). The basic pattern of distribution of the various enzymes was similar in the three species; species-specific variations were observed but cell-specific variations were more pronounced. The main activities of G-3-PDH and αGPDHM were observed in the seminiferous tubules; interstitial tissue showed moderate (G-3-PDH) and trace to weak (αGPDHM) activity. In contrast, αGPDHC activity was more marked in the interstitial tissue and less in the seminiferous tubules, especially in the mature germinal elements. LDH and ADH respectively showed strong and moderate activities in the interstitial tissue and seminiferous tubules. SADH was noticeable only in the interstitial tissue of buffalo. The activities of all enzymes other than αGPDHC increased during spermiogenesis. The physiological significance of the results is discussed in relation to the carbohydrate metabolism of the testis.