Isoflurane Attenuates Blood-Brain Barrier Disruption in Ipsilateral Hemisphere After Subarachnoid Hemorrhage in Mice

Background and Purpose-We examined effects of isoflurane, volatile anesthetics, on blood-brain barrier disruption in the endovascular perforation model of subarachnoid hemorrhage (SAH) in mice. Methods-Animals were assigned to sham-operated, SAH+vehicle-air, SAH+1%, or 2% isoflurane groups. Neurobehavioral function, brain water content, Evans blue dye extravasation, and Western blotting for sphingosine kinases, occludin, claudin-5, junctional adhesion molecule, and vascular endothelial cadherin were evaluated at 24 hours post-SAH. Effects of sphingosine kinase (N, N-dimethylsphingosine) or sphingosine-1-phosphate receptor-1/3 (S1P1/3) inhibitors (VPC23019) on isoflurane's action were also examined. Results-SAH aggravated neurological scores, brain edema, and blood-brain barrier permeability, which were prevented by 2% but not 1% isoflurane posttreatment. Two percent isoflurane increased sphingosine kinase-1 expression and prevented a post-SAH decrease in expressions of the blood-brain barrier-related proteins. Both N, N-dimethylsphingosine and VPC23019 abolished the beneficial effects of isoflurane. Conclusions-Two percent isoflurane can suppress post-SAH blood-brain barrier disruption, which may be mediated by sphingosine kinase 1 expression and sphingosine-1-phosphate receptor-1/3 activation. (Stroke. 2012; 43: 2513-2516.)