Age‐Related Changes in Skeletal Muscle and Small Mesenteric Arterial Function in Spontaneously Hypertensive Rats

Abstract

Essential hypertension is a chronic idiopathic medical condition that is characterized by elevated arterial blood pressure and is associated with increased risk of cardiovascular disease. Endothelial dysfunction is associated with increased age and a casual factor for the development of hypertension. Therefore, we hypothesized that endothelial dysfunction would be exacerbated by age to a greater extent in spontaneously hypertensive rats (SHRs) compared to Wistar‐Kyoto rats (WKY) control rats. Vascular function was assessed using pressure myography in skeletal muscle and mesenteric resistance arteries isolated from SHR and WKY across three age groups: young (16–17 weeks, n = 4/group), aged (62–64 weeks, n = 4/group) and old (88–100 weeks, n = 5/group). Phenylephrine‐induced vasoconstriction responses in either of the resistance arteries were not significantly different between WKY and SHR at any of the age groups. Endothelial‐dependent vasodilation in mesenteric arteries was not significantly different between WKY and SHR across age groups either. However, endothelium‐dependent vasodilation in the skeletal muscle resistance arteries was significantly enhanced in the young SHR compared to WKY, but not in the aged or old rats. Moreover, endothelial‐independent vasodilation in mesenteric arteries was significantly enhanced in SHR compared to WKY across all age groups, while this difference was only observed in the skeletal muscle resistance arteries of the young rats. Contrary to our hypothesis, these data suggest that endothelial dysfunction is not exacerbated by age in the resistance arteries of SHR.Support or Funding InformationResearch support: National Institute of Health grants: R01 HL137769 (JP), R01 HL088105 (LM‐L).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.