Deteriorated Vascular Homeostasis in Hypertension: Experimental Evidence from Aorta, Brain, and Pancreatic Vasculature

Abstract

Hypertension, as a primary risk factor for many fatal disorders, is prevalent in the elderly. There is wide literature on hypertension dealing with its biological and/or biochemical aspects; however, limited research is available on the multifactorial nature of hypertension from a mechanobiological standpoint. This study intended to study in parallel histopathological alterations and deviated protein expressions with the mechanical behavior of the hypertensive tissues. The Goldblatt (2K1C) method was chosen for induction of renovascular hypertension in rabbits. The microstructural and immunohistological characteristics of the aortic, pancreatic, and brain vasculature were investigated. The mechanical properties of the aortic tissue were also evaluated using biaxial tensile tests. Our findings indicated severe hypertrophy of the hypertensive vessels and declined content of intact smooth muscle cells. Most of the collagen I content of the wall was compromised and less functional type III collagen was highly expressed. Reversed collagen I to collagen III ratio was the main contributor to the hypertrophic and less stiff hypertensive vessel walls. The multifactorial nature of hypertension is illustrated, and smooth muscle cell detachment is identified as the sign of described degenerative cascades all along the arterial tree.