PATTERN OF LACTATE PRODUCTION AND STEROIDOGENESIS DURING GROWTH AND MATURATION OF MOUSE OVARIAN FOLLICLES INVITRO

A model culture system for the study of follicular metabolism has been developed from existing methods of whole-follicle culture. The modifi ed system mimics the in vivo growth and maturation of mouse ovarian fo llicles from primary to preovulatory stages and the modulating influen ces of the LH and FSH. This is the first study to demonstrate ovulatio n in vitro from individual ovarian follicles. The pattern of follicula r lactate production relative to steroidogenesis was studied throughou t in vitro follicular development over a period of 6 days. Twenty-four -hour samples of medium from individual follicles were analyzed for la ctate and pyruvate by an automated analytical technique, and for estra diol and progesterone by an immunoenzymatic method. Follicles produced remarkably large quantities of lactate and estradiol during FSH-stimu lated development in vitro. LH further stimulated lactate production b ut resulted in a significant decrease in estradiol secretion and an ov ulation rate of 30%. Progesterone production was not detectable throug hout the culture period, and follicles showed no evidence of pyruvate uptake. These findings demonstrate the validity of using this model cu lture system for the study of follicular metabolism and provide new in formation on the pattern of carbohydrate metabolism relative to steroi dogenesis during follicular growth and maturation.