Leukocyte networks and ovulation

Ovulation, the process whereby the oocyte is expelled from the interior of the follicle, is the final process of folliculogenesis. During the last decade, data have accumulated to suggest that tissue-bound leukocytes are major effector cells in several physiological processes within the reproductive tract. Some specific subclasses of leukocytes seem to be critically involved in the process of ovulation. The main components of this ovulatory process are degradation of the extracellular matrix (ECM) at the follicular apex and changes in the follicular vasculature. The leukocytes participate actively in these events by secretion of proteases and vasoactive substances. This review covers our current understanding of the mechanisms by which the leukocytes are attracted to the preovulatory follicle after the LH-surge and the roles that the activated leukocytes play in the follicle during the ovulatory period.