EFFECTS OF QUERCETIN ON RAT TESTIS AEROBIC GLYCOLYSIS

Lactate production by testicular fragments and isolated germinal cells at various stages of spermatogenesis was studied in aerobic and anero bic conditions. Several ATPase inhibitors were used to determine the r ole of ATPase activities in the control of aerobic lactate production; Aerobic glycolysis reached a high level in spermatogonia plus Sertoli cell and in primary spermatocyte populations. The activity was twice that found in early spermatids. Neither Na+-K+ ATPase nor mitochondria l F-1 ATPase seemed to participate directly in the control of aerobic glycolysis. The uncoupling of oxidative phosphorylation revealed the p otential role of F-1 ATPase in providing ADP and P-i for the glycolyti c pathway. Lactate production was inhibited by quercetin in all the ex perimental conditions tested. Quercetin (100 mu M) halted lactate prod uction by the Sertoli cell plus spermatogonia population and by isolat ed primary spermatocytes. In spermatids, quercetin inhibited aerobic g lycolysis only by 40%, even at higher concentrations. Only during the first meiotic prophase did quercetin inhibit the activity of a cytosol ic Ca2+-Mg2+ ATPase. This ATPase was also inhibited by erythro-9-[3-3( hydroxynonyl)]adenine (EHNA), suggesting that a cytoplasmic dynein cou ld be involved in the control of glycolysis in Sertoli cells, spermato gonia, and early primary spermatocytes.