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Updated: Aug 8, 2026

An In Vivo Estrogen Deficiency Mouse Model for Screening Exogenous Estrogen Treatments of Cardiovascular Dysfunction After Menopause
Published on: August 13, 2019
Estrogen replacement therapy decreases platelet-activating factor-acetylhydrolase activity in post-menopausal women
T Yoshimura1, A Ohshige, T Maeda
1Department of Obstetrics and Gynecology, Kumamoto University School of Medicine, Japan. yoshimur@kaiju.medic.kumamoto-u.ac.jp
Objective:
To examine the effects of estrogen replacement therapy on plasma platelet-activating factor-acetylhydrolase (PAF-AH) activity and the lipoprotein profile in post-menopausal women.
Method:
Eight post-menopausal women received conjugated equine estrogen (0.625 mg/day) orally for a period of 10 weeks. PAF-AH activity and lipid levels were measured in plasma samples obtained from each subject prior to treatment and after 2, 6, and 10 weeks of estrogen therapy.
Results:
Within 2 weeks of initiating estrogen treatment, a significant reduction in PAF-AH activity (-26%) was observed. Estrogen also caused significant decreases in total cholesterol (-8%), low-density lipoprotein-cholesterol (-24%), and the ratio of apolipoprotein B to A-II (-19%). On the other hand, levels of both high-density lipoprotein-cholesterol (18%) and triglyceride (31%) were elevated.
Conclusion:
Estrogen exerts a favorable effect on the lipoprotein profile, but decreased plasma PAF-AH activity may facilitate platelet aggregation thereby opposing protective effect of estrogen-replacement therapy with respect to thrombotic complications.
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