FIBRONECTIN CONCENTRATIONS CORRELATE WITH OVARIAN FOLLICULAR SIZE ANDESTRADIOL VALUES IN EQUINE FOLLICULAR-FLUID

The amounts of total protein, albumin, fibronectin, alpha 2-macroglobu lin (alpha 2-M), immunoglobulin G, ceruloplasmin and antithrombin were determined in fluids collected from 53 preovulatory equine follicles and compared with the contents of estradiol-17 beta, progesterone and androstenedione, with follicle size and the amounts of the equivalent proteins in normal equine plasma. The concentration of fibronectin and the fibronectin/albumin ratios increased significantly with follicle size and with follicular estradiol levels. The alpha 2-M levels and al pha 2-M/albumin ratios correlated with follicle size but not with horm one content. Both fibronectin and alpha 2-M were present in lower amou nts in follicular fluid compared with plasma while the other proteins were present in similar amounts. Among the proteins evaluated, there w as a positive correlation between the amount of the protein in the fol licular fluid and the molecular weight of the protein.