Renin in the female reproductive system.

The female reproductive system is characterized by the presence of local renin-angiotensin systems within the ovary and within the uterine lining. In the human ovary, renin arises from theca cells. In the uterus, the endometrium (uterine lining in the nonpregnant state) and the decidua (uterine lining in the pregnant state) are the major sources of renin. The primary form of renin produced by these extrarenal sources is prorenin. Angiotensin II, the active component of the renin cascade has a number of potential roles in the ovary and uterus. A key observation is that the human ovum and fetus is bathed in fluids rich in prorenin and angiotensin II.