Estradiol levels near the time of ovulation in the bonnet monkey (Macaca radiata)

In order to delineate the temporal relationship between the preovulatory estradiol 17β peak and ovulation in the bonnet monkey (Macaca radiata), venous blood from 6 monkeys was analyzed for estradiol 17β and total progestins near the time of ovulation in 15 normal menstrual cycles. In subsequent cycles, serial laparotomy was performed in 5 of the 6 animals studied and ovarian morphology was correlated to plasma estradiol 17β. Plasma progestin levels as well as visual observation and histological examination of the ovaries in this study indicate that ovulation in the bonnet monkey occurs 24-48 hr following a plasma estradiol 17β peak of at least 250 pg/ml.