The effect of glucose metabolism on murine follicle development and steroidogenesis in vitro

Previous studies have shown that mouse ovarian follicles produce large amounts of lactate during growth and maturation in vitro, suggesting a metabolic preference for glycolysis. Further investigations were therefore undertaken to determine firstly the effect of gonadotrophins on glucose uptake and secondly the role of glucose in follicle lactate production, development and steroidogenesis. Pre-antral mouse follicles were cultured individually in media containing different concentrations of glucose (1-5.5 mM) using a system which supported development to the pre-ovulatory stage within 5 days. Samples of media were removed every 24 h and analysed for oestradiol using an enzyme-linked immunosorbent assay technique and for glucose uptake and lactate production using a fluorimetric assay. Results showed that all the glucose consumed was converted to lactate, irrespective of the glucose concentration. Growth and steroidogenesis were also dependent on glucose concentration, and at concentrations below 2 mM, follicle development was significantly retarded. Results confirm that follicles adopt a predominantly glycolytic mode of energy production to sustain growth and steroidogenesis, and that the glycolytic rate is stimulated by gonadotrophins.