[Effect of intermittent normobaric hyperoxia and protein kinase C activity on blood - brain barrier permeability]

ABSTRACT

Studies have recently shown that intermittent normobaric hyperoxia has a significant therapeutic effect on the treatment of acute ischemia. In this study intermittent normobaric effect of hyperoxia and protein kinase C [PKC] activity in the blood - brain barrier [BBB] permeability and behavioral assessment were evaluated. In this experimental study 36 wistar rat were divided to 6 groups as follow normoxi [shem], normoxi+CHEL, normoxi+halt, normoxi+halt+CHEL, hyproxi+halt, hyperoxi+halt+CHEL, n=6 in each group. Chelerythrin chlorid [CHEL] was used as a systemically inhibitor of PKC. 24 hours later, rats were subjected to 60 min of right middle cerebral artery occlusion [MCAO]. The hyperoxia and normoxia groups were exposed to 95% and 21% respectively, for 4 h/day, 6 continuous days. After 24 h reperfusion, neurological deficit scores and BBB permeability was assessed. Data were analyzed using two way ANOVA and Bonferroni test. Preconditioning with intermittent normobaric hyperoxia decreased neurologic deficit scores and BBB permeability. Inhibition of PKC resulted in the increase of neurologic deficit scores; which improved with hyperoxia [P<0.001]. PKC inhibition, independent of hyperoxia improved the BBB function [P<0.001]. With the deployment of hyperoxia and specific subunits of PKC during the stroke, stability of BBB integrity and improvement of neurological deficit scores occur