Table 1.

The concentration of 17β-estradiol (nmol/l) in the inner chamber of the dialysis apparatus containing either native follicular fluid or trypsin treated before and after a 24-h incubation

Type	Native				Trypsin treated
Sample	Follicular fluid		Water		Follicular fluid		Water
	AVG	SEM	AVG	SEM	AVG	SEM	AVG	SEM
Pre-incubation estradiol concentration (nmol/l)	682.12	319.16	2.68	1.43	615.41	352.51	2.55	1.52
Post incubation estradiol concentration (nmol/l)	253.65	207.97	3.55	2.05	1.16	0.50	5.55	1.73

The estradiol concentration is also shown for the outer water-containing chamber. The results show that the ability of the follicular fluid to maintain an estradiol gradient was lost following treatment with trypsin, suggesting that it is maintained by the action of a binding protein. The average and standard error represent three separate experiments