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Rat ovarian renin: characterization and changes during the estrous cycle
R B Howard1, A G Pucell, F M Bumpus
1Department of Heart and Hypertension Research, Cleveland Clinic Foundation, Ohio 44195-5071.
Endocrinology
|November 1, 1988
Summary
Active renin exists in the rat ovary, with levels increasing at estrus, suggesting a functional ovarian renin-angiotensin system. This study characterizes ovarian renin and its cyclical changes.
Area of Science:
- Reproductive biology
- Endocrinology
- Biochemistry
Background:
- The renin-angiotensin system (RAS) plays crucial roles in cardiovascular and renal function.
- Its presence and function within the ovary are not fully understood.
- Investigating ovarian renin is key to understanding local RAS activity in reproduction.
Purpose of the Study:
- To characterize rat ovarian renin and its properties.
- To examine changes in ovarian renin levels throughout the rat estrous cycle.
- To investigate the localization and activation state of ovarian renin.
Main Methods:
- Biochemical characterization of ovarian renin activity and properties.
- Measurement of ovarian renin levels across different stages of the estrous cycle.
- Analysis of renin localization in hypophysectomized, diethylstilbestrol-treated rat ovaries.
Main Results:
- High concentrations of active renin were found in the rat ovary, with properties similar to kidney renin.
- Ovarian renin levels significantly increased (2-fold) at estrus.
- Ovarian renin was predominantly active (3:1 active to inactive ratio), unlike plasma renin, and localized to the theca-interstitial compartment.
Conclusions:
- Active renin is present in the rat ovary and its levels are cyclically regulated, increasing at estrus.
- Enhanced local production and activation of renin precursor likely contribute to increased ovarian renin at estrus.
- These findings support a functional renin-angiotensin system within the rat ovary.
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