Endocrine Abstracts

Angiogenesis, the process by which new blood vessels are formed from preexisting vasculature, is an essential feature of female reproductive cycles. Since angiogenesis involves migration and invasion of endothelial cells into surrounding tissues, proteases such as the Matrix metalloproteinases (MMPs), a family of soluble proteolytic enzymes, are critically important in this process (Rundhaug, 2005); moreover, they play a key role in extracellular matrix remodelling, a process that accomplishes ovarian follicular growth and ovulation (Riley, 2004). The aim of the present study was to verify a possible link between gelatinase (MMP2) activity and follicular growth in the swine. Follicular fluid was harvested by aseptical aspiration from antral follicles classified on the basis of their diameter into small (<3 mm), medium (3–5 mm) and large (>5 mm). Gelatinase concentration in the follicular fluids were measured by Matrix metalloproteinase-2 Biotrak Activity assay System that provides a specific and quantitative determination of active and pro-MMP-2. Fluids from small follicles showed significantly (P<0.01) higher enzyme levels (94.9±5 ng/ml, mean ±S.E.M.) than the other follicle classes; no significant differences were detected between medium and large follicles: (74.5±17, vs 71±16 ng/ml). These results suggest that the activity of MMP2 could be critically important during the early stages of antral follicular development, when tissue remodelling activity is intense and results in the formation of a complex vascular network necessary for the growing follicle.

Acknowledgements: This work was supported by a FIL grant (University of Parma)

Riley SC, Thomassen R, Bae SE, Leask R, Pedersen HG, & Watson ED, Matrix metalloproteinase-2 and -9 secretion by the equine ovary during follicular growth and prior to ovulation. Anim Reprod Sci. 2004 81 329–339