CHARACTERIZATION OF FOLLICULAR ENERGY-METABOLISM

It has been shown that mouse ovarian follicles have a large glycolytic capacity, and this study was undertaken to determine whether follicle s can develop normally using glycolysis alone. Pre-antral mouse follic les were grown using an in-vitro system which supports development to the preovulatory stage within 5 days. Cultures were maintained in eith er aerobic conditions in the presence of the inhibitor of oxidative ph osphorylation, sodium malonate, or under anaerobic conditions. Samples of media were removed every 24 h and analysed for oestradiol using an enzyme-linked immunosorbent assay (ELISA) technique and for lactate a nd glucose using a fluorometric assay. Follicle size, oestradiol produ ction and glycolytic rate were not significantly different between con trol and sodium malonate-treated follicles. Follicles cultured under a naerobic conditions showed significantly slower rates of growth and oe stradiol production compared with controls. However, the rate of glyco lysis was significantly higher during anoxia. Results indicated that a naerobic glycolysis may sustain limited periods of growth during the p re-antral phase, but that the presence of oxygen is vital to ensure no rmal development. It is concluded that pre-antral follicles can underg o development to the preovulatory stage using glycolysis alone, a feat ure which may allow them to conserve their limited supply of oxygen fo r other vital biosynthetic processes.