PECAM-1 mediates NO-dependent dilation of arterioles to high temporal gradients of shear stress

Zsolt Bagi, John A. Frangos, Jiunn Chern Yeh, Charles R. White, Gabor Kaley, Akos Koller

Research output: Contribution to journalArticlepeer-review

94 Scopus citations


Objective - In response to changes in wall shear stress (WSS) the vascular endothelium releases several factors, among others nitric oxide. On the basis of studies of endothelial cells in culture, suggesting that platelet endothelial cell adhesion molecule-1 (PECAM-1) is specifically involved in sensing and coupling high temporal gradients of fluid shear stress with activation of eNOS, we hypothesized that dilations of isolated skeletal muscle arterioles from PECAM-1 knockout mice (PECAM-KO) will be reduced to rapid increases in WSS elicited by increases in perfusate flow. Methods and Results - Small and large step increases in flow resulted in substantial dilations in arterioles of WT mice (45±4%), but they were markedly reduced in arterioles of PECAM-KO mice (22±5%). The initial slope of dilations, when WSS increased rapidly, was greater in vessels of WT than those of PECAM-KO mice (slopes: 0.378 and 0.094, respectively), whereas the second phase of dilations, when flow/shear stress was steady, was similar in the 2 groups (slopes: 0.085 and 0.094, respectively). Inhibition of eNOS significantly reduced the initial phase of dilations in arterioles from WT, but not from those of PECAM-KO mice. The calcium ionophore A23187 elicited similar NO-mediated dilation in both WT and PECAM-KO mice. Conclusions - In isolated arterioles of PECAM-KO mice activation of eNOS and consequent dilation by agonists is maintained, but the dilation to high temporal gradients of wall shear stress elicited by increases in perfusate flow is reduced. Thus, we propose that PECAM-1 plays an important role in the ability of the endothelium to sense and couple high temporal gradients of wall shear stress to NO-mediated arteriolar dilation during sudden changes in blood flow in vivo.

Original languageEnglish (US)
Pages (from-to)1590-1595
Number of pages6
JournalArteriosclerosis, thrombosis, and vascular biology
Issue number8
StatePublished - Aug 2005
Externally publishedYes


  • Arteriole
  • Endothelium
  • Flow-induced dilation
  • Nitric oxide
  • PECAM-1

ASJC Scopus subject areas

  • Cardiology and Cardiovascular Medicine


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