N-乙酰半胱氨酸和氯胺酮联用对脑缺血再灌注损伤的影响

Effects of combination of ketamine and N-acetylcysteine on brain damage following cerebral ischemia /reperfusion in mice

目的:研究巯基供体物质N 乙酰半胱氨酸(NAC)和非竞争性NMDA受体拮抗剂氯胺酮(KT)联用对小鼠脑缺血再灌注损伤的影响。方法:雄性ICR小鼠,随机分为假手术组、生理盐水组(0 .0 1L·g- 1)、氯胺酮组(15mg·kg- 1)、N 乙酰半胱氨酸组(75mg·kg- 1)和联合组(KT 15mg·kg- 1+NAC75mg·kg- 1)。参照蒋晓帆等建立的方法,制备局灶性短暂性脑缺血再灌注模型(tMCAO) ,再灌注后6、2 4h测定神经行为缺陷评分,处死TTC染色测定脑梗死面积百分比;制备不完全性脑缺血再灌注模型(2 VO) ,在再灌注0 .5、2和6h时取全脑制成10 %匀浆,比色法测定MDA含量、SOD和GSH Px活力。结果:(1)短暂性局灶性脑缺血再灌注后6、2 4h ,各组小鼠脑组织均有不同程度梗死灶、神经行为缺陷明显,与生理盐水组比较,药物联合组可显著改善缺血再灌注小鼠的神经行为缺陷(均为P <0 .0 1) ,减少脑梗死面积百分比(均为P <0 .0 1) ,药物单用对以上指标有轻度的改善作用(P >0 .0 5 )。(2 )联合用药可明显改善脑细胞损伤。(3)与假手术组比较,不完全性全脑缺血再灌注损伤0 .5、2和6h后,生理盐水组小鼠MDA含量显著升高(均为P <0 .0 1) ,SOD活性(均为P <0 .0 1)和GSH Px活性均显著降低(均为P <0 .0 1)。与生理盐水组比较。

AIM: To evaluate the effects of the combination of ketamine (KT) and N-acetylcysteine (NAC) on damage following cerebral ischemia/reperfusion in ICR mice. METHODS: Male ICR mice were randomly divided into seven groups: Sham group, NS (saline 0.1 ml·kg -1 ) group, KT (15 mg·kg -1 ) group, NAC (75 mg·kg -1 ) group, NAC+KT (75+15 mg·kg -1 ) group. (1) ICR mice underwent two hours cerebral ischemia by transient right middle cerebral artery occlusion (tMCAO) and followed 6 h and 24 h reperfusion. Then brains were prepared for the determination of the infarction volume. Before the death, neurological deficits were scored. (2) ICR mice subjected to five minutes ischemia by two common carotid arteries occlusion (2-VO) and followed 0.5 , 2 and 6 h reperfusion. Brains were prepared for the determination of the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and the content of MDA. RESULTS: (1) tMCAO produced severe neurological deficits, decreased the average score and brought about large infarction volume. KT, NAC showed the improvement of the average score and reduced infarction volume to some extent, and KT+NAC improved significantly. (2) The content of the MDA, the activities of GSH-Px and SOD in 2-VO mice deteriorated sharply, KT, NAC reduced the content of the MDA, enhanced the activities of GSH-Px and SOD, NAC+KT significantly ameliorated the levels of MDA, increased the activity of SOD and GSH-Px. CONCLUSION: The damage of cerebral ischemia/reperfusion leads to the decrease of neurological score, the increase of infarction volume, the reduction of activities of SOD and GSH-Px and the elevation of MDA. KT and NAC partly relieve the damage, and NAC and KT in combination attenuates the damage more effectively.