Integrin‐mediated Vasoconstrictor Function Declines with Age in Skeletal Muscle Resistance Arteries

Abstract

IntroductionVasoconstrictor responses decline with age in skeletal muscle resistance arteries. The mechanism for functional regulation of resistance artery contractility is not fully understood but has been proposed to involve impaired integrin signaling in vascular smooth muscle.ObjectiveThe purpose of this study was to test the hypothesis that RGD binding integrin‐mediated constrictor responses decline with age in skeletal muscle resistance arteries.MethodsSoleus muscle feed arteries (SFA) were isolated from young (4 mo) and old (24 mo) male Fischer 344 rats. SFA were cannulated with glass micropipettes and pressurized to 90 cm H2O for assessment of vasoconstrictor function. Vasoconstrictor responses were assessed using an a1 selective adrenergic agonist (phenylephrine; PE). To test the role of integrin signaling, constrictor responses were assessed in the absence or presence of an integrinblocking peptide (RGD) or a control peptide (RGE).ResultsConstrictor responses to PE were significantly impaired in old SFA relative to young SFA. In the presence of the RGD soluble peptide, constrictor responses to PE were significantly reduced in young SFA such that the young SFA responded like control (no treatment) old SFA. In the presence of the RGD peptide, constrictor responses to PE were further reduced in old SFA. Constrictor responses to PE were not altered by RGE in young or old SFA.ConclusionThe results of this study indicate that RGD binding integrin‐mediated constrictor function declines with age in SFA.Support or Funding InformationResearch support: National Institute on Aging, Sydney and J.L. Huffines Institute of Sports Medicine and Human Performance.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.