Changes of Interleukine-6 and Neuroglobin Expressions and the Effect of Kallikrein in Cerebral Ischemia Preconditioning Rats

Objective To investigate the neuroprotective mechanism of ischemic preconditioning and kallikrein.Methods 72 healthy male Sprague-Dawley(SD) rats were randomly divided into 3 groups: ischemia group(n=24),ischemic preconditioning group(n=24),and kallikrein intervention group(n=24).Each group was further divided into 4 subgroups according to the time of 12 h,1 d,2 d,and 3 d after re-ischemia(each subgroup n=6).The following indexes in 3 groups were investigated respectively: neurological function,infarct volume and hippocampal IL-6 expression and cortical Ngb expression.Results At the same point of time after ischemia,the score of neurological impairment,the infarct volume and the expression of IL-6 were lower in preconditioning group than those in ischemia group(P0.05,P0.01).Moreover,these indexes were much lower in intervention group(P0.05,P0.01).The expression of Ngb was higher both in preconditioning group and in intervention group than that in ischemia group(P0.01).However,there was no significant difference between preconditioning group and intervention group.Conclusions Cerebral ischemic preconditioning can protect the brain against the injury of the followed severe ischemia.Application of kallikrein after cerebral ischemia could increase this protection.