The study about cerebral ischemic preconditioning against cerebral ischemic injury by lowing the cerebral content of nitric oxide in rat

Objective:To assess the protective effect of cerebral ischemic preconditioning and the link between the pro- tective effect and nitric oxide (NO) in cerebral ischemic injury of rat.Methods:Ischemic preconditioning group rats were produced by clamping the bilateral common carotid arteries (BCCA) to occlude blood flow for 15 minutes.Following re- covery for 3 days,the middle cerebral artery occlusion (MCAO) models of rats were made by using a thread to occlude the right middle cerebral artery for 8 hours.The non-ischemic preconditioning group rats were suffered the same proce- dures except the BCCA were not clamped.Then the neurologic function wane of rats was estimated and the content of NO in cortex and hippocampus were measured by nitrite reduction.Results:(1)The neurologic disorders of the ischemic pre- conditioning group rats were less severe significantly than those of the non-ischemic preconditioning group rats (P＜0. 01).(2)The content of NO in cerebral cortex and hippocampus of the ischemic and self-control side of ischemic precondi- tioning group rats were less significantly than those of the non-ischemic preconditioning group rats (P＜0.05).Conclu- sions:Cerebral ischemic preconditioning hasprotection against the sequent cerebral ischemic injury of rat.The one of the neuroprotectivemechanisms of cerebral ischemic preconditioning maybe by reducing the content of NO in cerebraltissue of rat.