The neuroprotective effect of nimodipine in the time window on cerebral ischemia/ reperfusion in rats

Objective To investigate the effects of the therapy of nimodipine in the time window for reperfusion injury after focal cerebral ischemia in rats. Methods Sixty adult male Wistar rats were randomly divided into two groups, nimodipine, and control group. The nimodipine and control group once more divided into 2h, 3h, 4h, 5h, and 6h groups. A rat model of middle cerebral artery occlusion (MCAO) was induced by the intraluminal suture method; Reperfusion was performed each time stage after cerebral ischemia, respectively. At 20 minutes before reperfusion after cerebral ischemia, 12 h and 36 h after reperfusion, the medications were injected slowly into the tail veins of rats. The survival rate of rats was calculated 48 hours after cerebral ischemia/reperfusion, and the volumes of cerebral infarction and neurological deficit scores were measured. R e s u l t s ① The survival rate of rats in the two groups were 53.3% and 40%, respectively. The survival rate in nimodipine group is higher than that in the control group. But it was not statistical significance. ② Neurological deficit scores: Neurological deficit scores in nimodipine group were less than the control group. And the nimodipine 4h group were less than the control group(P0.05). ③ Cerebral blood flow in rats: The nimodipine group has a higher cerebral blood flow (P0.05). And the 3h with 4h groups are higher cerebral blood flow (P0.05). ④ The volumes of cerebral infarction in rats: The volumes of cerebral infarction in nimodipine group was less than control group and 2h group has statistical significance (P0.05). Conclusion The neuroprotective effects of nimodipine in the time window on focal cerebral ischemia/reperfusion injury in rats were 2h to 4h.