Effects of quercetin on rat testis aerobic glycolysis

Abstract

Lactate production by testicular fragments and isolated germinal cells at various stages of spermatogenesis was studied in aerobic and anerobic conditions. Several ATPase inhibitors were used to determine the role 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 mitochondrial F1ATPase seemed to participate directly in the control of aerobic glycolysis. The uncoupling of oxidative phosphorylation revealed the potential role of F1ATPase in providing ADP and Pifor the glycolytic pathway. Lactate production was inhibited by quercetin in all the experimental conditions tested. Quercetin (100 μM) halted lactate production by the Sertoli cell plus spermatogonia population and by isolated primary spermatocytes. In spermatids, quercetin inhibited aerobic glycolysis only by 40%, even at higher concentrations. Only during the first meiotic prophase did quercetin inhibit the activity of a cytosolic Ca2+–Mg2+ATPase. This ATPase was also inhibited by erythro-9-[3-3(hydroxynonyl)]adenine (EHNA), suggesting that a cytoplasmic dynein could be involved in the control of glycolysis in Sertoli cells, spermatogonia, and early primary spermatocytes.Key words: quercetin, aerobic glycolysis, germ cells, cytosolic dynein, mitochondrial ATPase.