Abstract
Changes in serum inhibin concentrations during the menstrual cycle were studied in 6 Japanese monkeys (Macaca fuscata fuscata) by a heterologous radioimmunoassay (RIA) based on a bovine RIA. Serum levels of estradiol-17β, progesterone, LH and FSH were also monitored. Inhibin levels in the serum were low during the early and midfollicular phases, followed by a slight increase during the late follicular phase. A marked increase in serum inhibin was found during the luteal phase. Changes in serum inhibin during the luteal phase were positively correlated with those in serum progesterone, whereas serum FSH remained suppressed during the luteal phase. These results suggest that both the corpora lutea and the antral follicles are the sources of circulating inhibin in the female Japanese monkey.
