Selective ER-α agonist alleviates vascular endothelial dysfunction in ovariectomized type 2 diabetic rats

Area of Science:

• Endocrinology
• Cardiovascular Science
• Pharmacology

Background:

• Postmenopausal diabetic women face increased vascular deficits.
• 17β-estradiol's vasculoprotective effects are diminished in diabetic individuals.
• Differential estrogen receptor (ER-α and ER-β) activation may explain this dichotomy.

Purpose of the Study:

• To identify the specific estrogen receptor target for vasculoprotection in postmenopausal diabetic women.
• To investigate the role of ER-α and ER-β in diabetic vascular complications.

Main Methods:

• Utilized ovariectomized type 2 diabetic rats.
• Assessed glycemic and lipid profiles, endothelial function (ACh-induced relaxation), endothelial integrity, and oxidative/inflammatory markers.
• Correlated these markers with aortic endothelial nitric oxide synthase (eNOS) levels.
• Treated rats with selective ER-α agonist, ER-β agonist, and 17β-estradiol.

Main Results:

• Diabetic rats exhibited impaired glycemic/lipid profiles, reduced endothelial function, and increased oxidative stress.
• Selective ER-α agonist treatment significantly improved these vascular parameters and increased eNOS levels.
• 17β-estradiol partially ameliorated the alterations, while ER-β agonist had no significant effect.

Conclusions:

• Selective ER-α activation effectively mimics the beneficial cardiovascular effects of estrogen in a diabetic context.
• ER-α is a potential therapeutic target for preventing vascular complications in postmenopausal diabetic women.
• Targeting ER-α may offer a novel strategy for cardiovascular protection in this high-risk group.