Figure 1: Changes in 17-β-estradiol plasma levels after ovariectomy. Plasma estradiol before ovariectomy (Day 0) and 7, 4,21 and 28 days after ovariectomy. Plasma estradiol decreased over time in ovariectomized rats that received an empty Silastic implant (OVX +Silastic Empty) and in those that did not receive an implant (OVX); (ANOVA p<0.0001 [F(94, 29))=25.86 followed by FISHERLSD multiple comparison test]. No difference in estradiol levels was detected between these groups throughout the 4 weeks postsurgery. Rats that received the placebo cholesterol pellet (OVX +Placebo Pellet) did not show a significant decrease in basal estradiol levels after ovariectomy (p>0.05). The estradiol value of the intact animals (white bar) is the average of the all the animals, before they were ovariectomized and assigned to the different groups. At time point 0, n=29; All OVX n=7; OVX+ empty Silastic n=14; OVX+Cholesterol pellet n=8. Data are expressed as mean + standard error of the mean (S.E.M.).