Angiotensin Ⅱ type 1 receptor autoantibody (AT1-AA) is involved in ovulatory disorders: AT1-AA impairs spindle and chromosome organization.

Ovulatory disorders are a major cause of infertility. Studies have shown that the renin-angiotensin system (RAS) plays a vital role in the female reproductive system. The angiotensin Ⅱ type 1 receptor (AT1R), an important mediator of the RAS, may induce anovulation when activated. Previous studies have shown that the levels of AT1R autoantibody (AT1-AA) are significantly higher in the serum of infertile women and are negatively correlated with the oocyte maturation rate. However, systematic understanding of the changes of AT1-AA associated with female ovulatory dysfunction remains limited. In this study, participants were divided into three groups: healthy controls, tubal obstruction group, and ovulatory disorders group. The levels of AT1-AA in serum and follicular fluid were determined using ELISA. The results showed that AT1-AA levels were elevated in both serum and follicular fluid of the ovulatory disorders group compared to the tubal obstruction group. The levels of AT1-AA were negatively correlated with high-quality embryos in the ovulatory disorders group. Follicular fluid AT1-AA levels were an independent risk factor for developing ovulatory disorders. Furthermore, AT1-AA impeded mouse oocyte maturation in vitro, and this effect was suppressed by the second extracellular loop peptide of AT1R. Our findings indicate that follicular fluid AT1-AA is associated with ovulatory disorders and impaired oocyte maturation.