Figure 1. Reproductively old mice weigh more than young mice but respond similarly to hormone stimulation. (A) Graph showing the average number of each follicle class per ovarian section (every fifth section of serially sectioned ovaries was counted; N = 20 ovaries from 5 reproductively young and 5 old mice). The inset shows the average number of antral follicles and other (degenerate) follicles per ovarian section with a different scale. T-tests were performed within each follicle class; asterisks denote P < 0.0001. (B) Weights of reproductively young and old mice (n = 11 young and 11 old mice). A t-test was performed; asterisks denote P < 0.0001. (C) Serum estradiol levels were assessed (reportable range 3-300 pg/mL). A t-test was performed and there was no difference in estradiol levels between age cohorts. (D) Serum progesterone levels were assessed (reportable range 0.15-40 ng/mL). A t-test was performed and there was no difference between age cohorts. Data are represented as mean ± SEM. N = 20 samples for hormone analysis.