In vivo endothelial denudation disrupts smooth muscle caveolae and differentially impairs agonist-induced constriction in small arteries

Abstract

Experiments were performed to determine the effects of endothelial denudation in vivo on vasoconstrictor responses of mouse tail artery segments in vitro. A sterile wire (70 microm diameter) was inserted into tail arteries of anesthetized mice to mechanically denude the endothelium, and the animals were allowed to recover for 48 hours. The function of pressurized tail artery segments was then studied in vitro. Intimal injury markedly reduced endothelium-dependent relaxation to acetylcholine. Constriction evoked by the selective alpha1-adrenoceptor (alpha1-AR) agonist, phenylephrine, was not affected by in vivo endothelial denudation, indicating that the contractile function of vascular smoot..