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

Aging-related changes in vascular stiffening and permeability are associated 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 damage levels. We isolated carotid arteries from ovariectomized (OVX) rats that underwent 1 yr of estrogen treatment with subcutaneous pellets and a subsequent 1 mo of cessation of treatment. Endothelial layer permeability and arterial compliance were determined using quantitative fluorescence microscopy. Endothelial layer permeability was reduced with estradiol treatment (estrogen groups, 2.58 +/- 0.21 ng dextran x min(-1) x cm(-2) vs. nonestrogen groups, 4.01 +/- 0.30 ng dextran x min(-1) x cm(-2); P < 0.05). Additionally, arteries from animals treated with estradiol had an increased compliance index (estrogen groups, 82.9 +/- 3.8 mm2. Torr vs. nonestrogen groups, 69.3 +/- 3.2 mm2. Torr; P < 0.05). Estradiol treatment also reduced levels of pentosidine, which is a specific marker of glycoxidative damage (estrogen groups, 0.11 +/- 0.03 pmol pentosidine/nmol collagen vs. nonestrogen groups, 0.20 +/- 0.03 pmol pentosidine/nmol collagen; P < 0.05). These results indicate that estradiol has multiple chronic vasculoprotective effects on the artery wall to maintain normal vascular wall function.