Role of soluble epoxide hydrolase in the sex-specific vascular response to cerebral ischemia

J Cereb Blood Flow Metab. 2009 Aug;29(8):1475-81. doi: 10.1038/jcbfm.2009.65. Epub 2009 May 27.

Abstract

Soluble epoxide hydrolase (sEH), a key enzyme in the metabolism of vasodilator eicosanoids called epoxyeicosatrienoic acids (EETs), is sexually dimorphic and suppressed by estrogen. We determined if the sex difference in blood flow during focal cerebral ischemia is linked to sEH. Soluble epoxide hydrolase expression in brain, hydrolase activity in cerebral vessels, and plasma 14,15-dihydroxyeicosatrienoic acid (14,15-DHET) were determined in male and female wild-type (WT) and sEH knockout (sEHKO) mice. Male, female, and ovariectomized female WT and sEHKO mice were subjected to 2-h middle cerebral artery occlusion (MCAO) and infarct size was measured at 24 h of reperfusion. Laser-Doppler cortical perfusion during MCAO was compared among groups and differences in cortical blood flow rates were confirmed using in vivo quantitative optical microangiography. Cerebrovascular expression and activity of sEH and plasma 14,15-DHET were lower in WT female than male mice, and blood flow during MCAO was higher and infarct size was smaller in WT female compared with male mice. Sex differences in cerebral blood flow and ischemic damage were abolished after ovariectomy and were absent in sEHKO mice. We conclude that sEH is an important mechanism underlying sex-linked differences in blood flow and brain damage after cerebral ischemia.

MeSH terms

  • 8,11,14-Eicosatrienoic Acid / analogs & derivatives
  • 8,11,14-Eicosatrienoic Acid / blood
  • Animals
  • Blood Flow Velocity / physiology*
  • Blotting, Western
  • Brain Ischemia / enzymology
  • Brain Ischemia / pathology
  • Brain Ischemia / physiopathology*
  • Disease Models, Animal
  • Enzyme-Linked Immunosorbent Assay
  • Epoxide Hydrolases / genetics
  • Epoxide Hydrolases / metabolism
  • Epoxide Hydrolases / physiology*
  • Estrogens / physiology
  • Female
  • Infarction, Middle Cerebral Artery / complications
  • Male
  • Mice
  • Mice, Knockout
  • Ovariectomy
  • Sex Characteristics*
  • Solubility

Substances

  • 14,15-dihydroxyeicosatrienoic acid
  • Estrogens
  • Epoxide Hydrolases
  • 8,11,14-Eicosatrienoic Acid