The exact reason(s) for the differences in FSH and LH action on the activities of PFK and PK versus MDH is not known; however, the results strongly indicate that some of the major regulatory steps of glycolysis and the Krebs cycle may be influenced differently by FSH and LH, and that the influence varies with the maturational status of the follicle. Nilsson has demonstrated that LH significantly stimulates lactic acid production in eCG-treated rat preovulatory follicles in vitro, indicating an increase in glycolysis by gonadotropins; and this mode of energy production may be favored in vitro for preantral follicles as observed in the present studies. flovent inhaler
Moreover, follicular ability to metabolize pyruvate further via the Krebs cycle seems to depend, at least partly, on the type of hormonal stimulus and developmental status of the follicle. Whereas mouse preantral follicles with theca can grow to the antral stage under experimental anaerobic culture conditions, increased follicular MDH activity in the present studies clearly indicates that under normal physiological conditions, endocrine and paracrine factors stimulate the overall energy production cycle resulting in adequate ATP formation for follicle development.