Elemental composition of rabbit antral fluid during preovulatory follicular swelling

Electron probe microanalysis was used to determine the concentrations of Na, Cl, K Ca, Mg, S and P in samples of follicular fluid, ovarian vein serum and peripheral venous serum obtained from virgin rabbits at 2-h intervals up to 10 h after injection of hCG. Throughout this 10-h period the elemental composition of follicular fluid was essentially the same as that of blood serum. However, there was a significant drop in follicular fluid Ca relative to blood during the 10-h period which may reflect Ca involvement in the regulation of oocyte maturation. Significant differences were also found between follicles within rabbits for K and P concentrations.