Ovarian prorenin-renin-angiotensin system

Area of Science:

• Reproductive Endocrinology
• Biochemistry

Background:

• Renin is traditionally viewed as a kidney-secreted enzyme crucial for angiotensin production.
• Emerging evidence points to an extra-renal renin-angiotensin system within the ovaries, potentially influencing reproductive processes.

Purpose of the Study:

• To investigate the presence and role of an ovarian prorenin-renin-angiotensin system.
• To explore the regulation of this system in relation to reproductive events like the menstrual cycle and early pregnancy.

Main Methods:

• Analysis of prorenin and active renin levels in ovarian follicular fluid and plasma.
• Monitoring hormonal changes during the menstrual cycle, after gonadotropin stimulation, and during early pregnancy.
• Comparison of prorenin levels in women with and without ovarian function.

Main Results:

• High concentrations of inactive prorenin, with minimal active renin, found in human ovarian follicular fluid.
• Plasma prorenin significantly increases during the LH surge and early pregnancy, correlating with hCG levels.
• Ovaries identified as the source of increased plasma prorenin during early pregnancy.

Conclusions:

• Prorenin is synthesized and secreted by ovarian structures (mature follicle, corpus luteum) in response to LH/hCG.
• An ovarian renin system, regulated by prorenin fluctuations, appears to exist and is linked to reproductive function.