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An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Raloxifene prevents endothelial dysfunction in aging ovariectomized female rats
Chi Ming Wong1, Xiaoqiang Yao, Chak Leung Au
1Li Ka Shing Institute of Health Sciences, Chinese University of Hong Kong, Hong Kong, China.
Vascular Pharmacology
|March 18, 2006
Summary
Aging female rats provide a better model for menopause-related cardiovascular risk. Raloxifene therapy improved vascular function by increasing nitric oxide availability in ovariectomized rats.
Area of Science:
- Cardiovascular Science
- Endocrinology
- Pharmacology
Background:
- Cardiovascular risk increases post-menopause, but appropriate animal models are lacking.
- Ovariectomy in young animals doesn't fully replicate menopausal changes, including aging effects.
- Aging female rats may offer a more relevant model for studying menopausal cardiovascular alterations.
Purpose of the Study:
- To investigate vascular reactivity changes in aging ovariectomized rats.
- To assess the effects of chronic raloxifene therapy on vascular function and eNOS protein.
- To establish a more accurate animal model for post-menopausal cardiovascular research.
Main Methods:
- Compared aortic ring vascular reactivity in sham-operated, ovariectomized, and raloxifene-treated aging rats.
- Measured isometric tension in aortic rings to assess responses to phenylephrine and other agents.
- Quantified endothelial nitric oxide (NO) release and eNOS protein expression.
Main Results:
- Ovariectomized rats showed impaired vascular response to phenylephrine, indicating reduced nitric oxide bioavailability.
- Raloxifene treatment normalized phenylephrine-induced contractions in ovariectomized rats.
- Vascular relaxation to thapsigargin and acetylcholine was enhanced by raloxifene.
- Aortic eNOS protein levels remained unchanged across all groups.
Conclusions:
- Chronic raloxifene administration improves endothelial nitric oxide bioavailability in aging ovariectomized rats.
- Raloxifene enhances vascular function without altering eNOS protein expression.
- The aging ovariectomized rat model is valuable for studying menopausal cardiovascular changes and therapeutic interventions.
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