Vascular dysfunction in S1P2 sphingosine 1-phosphate receptor knockout mice

John N. Lorenz, Lois J. Arend, Rachel Robitz, Richard J. Paul, A. John MacLennan

Research output: Contribution to journalArticle

Abstract

There is growing evidence that sphingosine 1-phosphate (S1P) plays an important role in regulating the development, morphology, and function of the cardiovascular system. There is little data, however, regarding the relative contribution of endogenous S1P and its cognate receptors (referred to as S1P1-5) to cardiovascular homeostasis. We used S1P2 receptor knockout mice (S1P2-/-) to evaluate the role of S1P2 in heart and vascular function. There were no significant differences in blood pressure between wild-type and S1P2 -/- mice, measured in awake mice. Cardiac function, evaluated in situ by using a Millar catheter, was also not different in S1P2 -/- mice under baseline or stimulated conditions. In vivo analysis of vascular function by flowmetry revealed decreases in mesenteric and renal resistance in S1P2-/- mice, especially during vasoconstriction with phenylephrine. In intact aortic rings, the concentration-force relations for both KCl and phenylephrine were right shifted in S1P2-/- mice, whereas the maximal isometric forces were not different. By contrast, in deendothelialized rings the concentration-force relations were not different but the maximal force was significantly greater in S1P2-/- aorta. Histologically, there were no apparent differences in vascular morphology. These data suggest that the S1P2 receptor plays an important role in the function of the vasculature and is an important mediator of normal hemodynamics. This is mediated, at least in part, through an effect on the endothelium, but direct effects on vascular smooth muscle cannot be ruled out and require further investigation.

Original languageEnglish (US)
Pages (from-to)R440-R446
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume292
Issue number1
DOIs
StatePublished - Jan 1 2007

Keywords

  • Blood flow
  • Endothelium
  • Lysosphingolipids
  • Myocardial contractility
  • Vascular smooth muscle

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

Fingerprint Dive into the research topics of 'Vascular dysfunction in S1P<sub>2</sub> sphingosine 1-phosphate receptor knockout mice'. Together they form a unique fingerprint.

  • Cite this