We have previously demonstrated that FSH stimulates DNA synthesis and steroidogenesis and growth factor receptor induction in human preantral follicles. Boland et al. have documented that the degree of lactate production in vitro by preantral mouse follicles with surrounding theca/stromal tissue increases steadily as follicles develop into the antral stage, and that FSH either alone or in combination with LH stimulates the rate of lactate production. buy birth control online
This result corroborates the increased PFK activity observed in response to gonadotropins in the present studies; however, human preantral follicles also exhibit an increase in PK activity when exposed in vitro to FSH, suggesting that human preantral follicles are able to metabolize glucose to pyruvate under the proper hormonal milieu. Although we do not know the relative levels of pyruvate or lactate in human follicle culture medium, the pyruvate produced by the mouse follicle-stroma complex apparently gets converted to lactate, thus keeping the pyruvate level unchanged throughout culture. In our protocol, human preantral follicles were free of surrounding stromal tissue, and follicles were cultured for 24 h during which no significant follicle growth occurs. Human preantral follicles in class 2 develop into antral follicles by 72-96 h in culture.