Functional and structural modifications associated with hypertension, obesity and diabetes in the resistance vasculature
Functional and structural modifications associated with hypertension, obesity and diabetes in the resistance vasculature
Abstract
Cardiovascular diseases are considered the leading cause of death nowadays. Hypertension, obesity and type-2 diabetes are deemed major risk factors for the development of cardiovascular diseases. In essential hypertension, one of the most important structural changes is the inward remodeling of the resistance arteries. I found that the mechanical properties of inwardly remodeled cremasteric-arterioles from rats are affected. Furthermore, it is the F-actin components of the cytoskeleton the ones that are strongly modified. In old spontaneously hypertensive rats, my results showed that, resistance arteries undergo hypertrophic inward remodeling; and, adrenergicvasoconstriction and vasodilation pathways are impaired. In diet-induced-obesity, micemesenteric arterioles were observed to undergo remodeling of the extracellular matrix components. Obesity and type-2 diabetes have been associated with insulin resistance, endothelial dysfunction and arterial stiffening. Jejunal-submucosal arterioles from diabetic obese patients had a reduced vasorelaxation to insulin in comparison to obese non-diabetics, while acetylcholine-vasodilation was similar in both groups. Reduced amounts of the subunit-alpha of the insulin receptor and MMP-9 were found in diabetics as well. This suggests that, in type-2 diabetes, the presence of a blunted insulinvasodilation response is a form of endothelial dysfunction that is not correlated with the body-to-mass index, but whose mechanism may be related with the activity of MMPs.
Degree
Ph. D.
Thesis Department
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