Fig. 1

Excessive NGF inhibited mouse oocyte maturation. a Excessive NGF in the follicular fluid of Chinese PCOS patients. Concentration of NGF in human follicular fluid (hFF) of Chinese non-PCOS patients (n = 9) and PCOS patients (n = 13) was determined by ELISA. b–c COCs were cultured with the indicated concentration of NGF for 18 h (b) or with 100 ng/ml NGF for the indicated times (c) in the presence or absence of 10 μM K252α. The proportion of PB1 extrusion was then calculated. The number of COCs for each group was ≥35. Representative data are presented as mean ± SEM. *, p < 0.05; **, p < 0.01