Effects of L-Arginine and 7-Nitroindazole in the Gerbil Model of Global Cerebral Ischemia

ABSTRACT

PURPOSE: This study was performed to determine whether L-Arginine would improve or worsen the neurologic out-come after ischemic brain injury and whether 7- Nitroindazole (7-NI, inhibitors of neuronal nitric oxide (NO) synthase inhibitor) would improve or worsen. METHODS: Five (5) groups (N =11 to 14) of anesthetized gerbils were subjected to 10 min of global cerebral ischemia by means of a bilateral carotid artery occlusion. One group (N =11) was the control group. In a second group (N =12), the animals were pretreated with intraperitoneal L-Arginine (300 mg/kg) one hour before ischemic insult. In a third group (N =12), pretreatment with L-Arginine was performed in the same manner and intraperitoneal 7-NI were given at the time of reperfusion and 2 hours after reperfusion. The animals of a fourth group (N =12) were treated with 7-NI in the same manner without any pretreatment with L-Arginine. The animals in the last group (N =14) underwent sham operations. RESULTS: Compared with control group, concomittent treatment with L-Arginine and 7-NI showed no significant improvement in the neurological cell survival rate. Also, group pretreated with L-Arginine only showed a similar out-come. The group treated with 7-NI at the time of reperfusion and 2 hours after reperfusion showed a significant improvement in the neurological cell survival rate compared with the control group and the other two experimental groups (p<0.05). CONCLUSION: In the ischemia-reperfusion injury of global ischemia in gerbils, NO from endothelial NO synthase has no important role in the neurological outcome.