Studies on anti-müllerian hormone production, action, and regulation in the primate ovary: Insight into human folliculogenesis

Although examined over the past decade, our current understanding of anti-Müllerian hormone (AMH) actions in the ovary is primarily based on rodent studies. However, not only are the conclusions from rodent studies inconsistent, but there are apparent species differences in follicular AMH actions according to data from nonhuman primate and human studies. Although the relationship between AMH and clinical outcome in assisted reproduction has been studied extensively, data thus far in humans are almost all correlative. Therefore, studies in nonhuman primates are critical to clearly identify the role of AMH in ovarian physiology due to the similarity of their ovarian structure, function, and regulation to those of women. AMH is produced heterogeneously by primate preantral follicles, with an increased expression during subsequent growth till declining after antrum formation. Actions of AMH appear stage-dependent in the primate ovary in contrast to most rodent data. AMH promotes preantral follicle growth and inhibits antral follicle maturation in primates. The in vitro and in vivo studies conducted in nonhuman primates provide mechanistic data on the role of AMH, as a paracrine effector, in the primate ovary both qualitatively and quantitatively at the molecular, cellular and systemic levels. New information generated from the nonhuman primate studies for the stage-specific AMH manipulation could portend novel therapeutic approaches to regulate follicular development clinically in women, including those with primary ovarian insufficiency, polycystic ovarian syndrome, and reproductive aging.