Chronic estradiol treatment attenuates stiffening, glycoxidation, and permeability in rat carotid arteries

Aging-related changes in vascular stiffening and permeability are associate d with cardiovascular disease. We examined the interaction of estradiol on the aging process in vascular tissue from rats by assessing the changes in endothelial layer permeability, arterial compliance, and glycoxidative dama ge levels. We isolated carotid arteries from ovariectomized (OVX) rats that underwent 1 yr of estrogen treatment with subcutaneous pellets and a subse quent 1 mo of cessation of treatment. Endothelial layer permeability and ar terial compliance were determined using quantitative fluorescence microscop y. Endothelial layer permeability was reduced with estradiol treatment (est rogen groups, 2.58 +/-0.21 ng dextran.min(-1).cm(-2) vs. nonestrogen groups , 4.01 +/-0.30 ng dextran.min(-1).cm(-2); P<0.05). Additionally, arteries f rom animals treated with estradiol had an increased compliance index (estro gen groups, 82.9<plus/minus>3.8 mm(2).Torr vs. nonestrogen groups, 69.3 +/- 3.2 mm(2).Torr; P<0.05). Estradiol treatment also reduced levels of pentosi dine, which is a specific marker of glycoxidative damage (estrogen groups, 0.11<plus/minus>0.03 pmol pentosidine/nmol collagen vs. nonestrogen groups, 0.20 +/-0.03 pmol pentosidine/nmol collagen; P<0.05). These results indica te that estradiol has multiple chronic vasculoprotective effects on the art ery wall to maintain normal vascular wall function.