OBJECTIVETo observe the expression of endothelial nitric oxide synthase (eNOS)and nervous nitric oxide synthase (nNOS) in rats during cerebral ischemia/reperfusion (CI/R) and study if change will be happen in subgroup between eNOS and nNOS during earlier period of CI/R.

METHODSA total of 60 Wistar rats weighting 200-280 g, supplied by Animal Center of China Medical University, were divided into 6 groups (n=10) (sham operation group; ischemia 1 h, 2 h group; reperfusion 0.5 h, 1 h, 2 h group). Female and male was half-and-half. Cerebral ischemia/reperfusion injury was induced by a 2-hour suture occlusion of the unilateral middle cerebral artery, immediately after suture withdrawal to allow reperfusion, eNOS and nNOS expressions were examined by the method of immunohistochemistry.

RESULTSeNOS expressions increased in 1-hour during ischemia, keeping up with decreasing until reperfusion 2-hour. While nNOS expressions increased in 2-hour between ischemia and reperfusion.

CONCLUSIONChanges of expression between eNOS and nNOS in rats during cerebral ischemia/reperfusion are different. This may be related with ischemia and reperfusion injury.