Anti-Mü̈llerian Hormone (AMH) Intermediates Ovarian Reservation and Ovarian Aging

Abstract

In female, anti-Mü̈llerian hormone (AMH) is released from granulosa cells of growing follicles and inhibits primordial-primary follicle transition and reduces FSH-sensitivity to develop preantral follicles to antral follicles. Therefore, AMH is considered to be related to ovarian aging. Indeed, AMH serum level decreases by aging. Old (7 - 11 months) female Amh knockout (KO) mice tended to have lower delivery rate, compared to wild type animals in the same range of age. The ovarian weight was increased until 7 month in wild type mice but decreased at 7 month in Amh KO mice. Relative ovaian weight to body weight was no changed after maturation but not in Amh KO mice. We conducted qPCR on ovaries targeting Kitl, Kit, Gdnf and Gfra1 which are known to involve in primordial-primary follicle transition. The numbers of primordial follicles were significantly many in Amh KO mice in ≥ 6 wk and ≥ 3 m groups than wild type mice in same age groups. However, its number was significantly fewer in Amh knockout mice than wild type mice of the same age groups. Kitl, Kit, Gdnf, Gfra1 and Bmpr1a mRNAs gradually increased by aging after maturation. However, expression profiles in Amh KO mice were different from wild type. The expression levels of Bmpr1a mRNA, type I receptor of AMH, decreased in ≥ 3 m and ≥7 m Amh KO groups, compared to wild type. On the other hand, ratio of p-YAP/YAP was significantly decreased from 6 wks to older age. Based on these results, it is suggested that AMH may control primordial-primary follicle transition and ovarian reservation by YAP signaling.