不同剂量乳化异氟醚预处理对大鼠局灶性脑缺血再灌注损伤的影响

目的 探讨不同剂量乳化异氟醚预处理对大鼠局灶性脑缺血再灌注损伤的影响.方法 雄性SD大鼠96只,体重250～300 g,采用大脑中动脉线栓法制备大鼠局灶性脑缺血再灌注模型.大鼠随机分为6组(n=16),假手术组(S组)腹腔注射生理盐水(NS)10.5 ml/kg,24 h后只分离血管;缺血再灌注组(I/R组)腹腔注射NS 10.5 ml/kg,24 h后制备模型;低剂量乳化异氟醚预处理组(L组)、中剂量乳化异氟醚预处理组(M组)、高剂量乳化异氟醚预处理组(H组)和脂肪乳剂组(IL组)分别腹腔注射8%乳化异氟醚3.5 ml/kg+NS 7.0 ml/kg、8%乳化异氟醚7.0 ml/kg+NS 3.5 ml/kg、8%乳化异氟醚10.5 ml/kg和30%脂肪乳10.5 ml/kg,24 h后制备模型.于缺血前10 min和再灌注10 min时记录体温、心率和呼吸频率.再灌注24 h时行神经功能缺陷评分,然后取脑组织,测定脑梗死体积,行凋亡细胞计数,并观察脑组织病理学结果.结果 大鼠脑缺血再灌注时体温升高,心率加快,呼吸频率减慢.与S组比较,其余各组神经功能缺陷评分、脑梗死体积和凋亡细胞计数均升高(P＜0.05);与I/R组比较,L组、M组和H组神经功能缺陷评分、脑梗死体积和凋亡细胞计数均降低(P＜0.05),IL组差异无统计学意义(P＞0.05);L组、M组和H组神经功能缺陷评分、脑梗死体积和凋亡细胞计数依次降低(P＜0.05).结论乳化异氟醚可减轻大鼠局灶性脑缺血再灌注损伤,且呈剂量依赖性.

Effect of preconditioning with different doses of emulsified isoflurane on focal cerebral ischemia-reperfusion injury in rats

Objective To investigate the effect of preconditioning with different doses of emulsified isoflurane on focal cerebral ischemia-reperfusion (I/R) injury in rats. Methods Ninety-six male SD rats were randomly divided into 6 groups ( n = 16 each): sham operation group (group S), I/R group, low, median and high doses of emulsified isoflurane preconditioning group (group L, M, H) and intralipid group (group IL). Middle cerebral artery occlusion was produced by inserting a nylon thread. In group S, intraperitoneal normal saline (NS)10.5 ml/kg was injected, but the artery was only exposed 24 h later. In group I/R, intraperitoneal NS 10.5 ml/kg was injected, and the model was established 24 h later. In group L, M, H and IL, 8% emulsified isoflurane 3.5 ml/kg+NS 7.0 ml/kg, 8% emulsified isoflurane 7.0 ml/kg + NS 3.5 ml/kg, 8% emulsified isoflurane 10.5 ml/kg and 30% intralipid 10.5 ml/kg were injected intraperitoneally respectively, and then the model was established 24 h later. The temperature, HR and RR were recorded at 10 min before ischemia and at 10 min of reperfusion. The neurological deficit was scored, the cerebral infarct volume and apoptosis in neurons were detected, and microscopic examination of ischemic penumbra region was performed at 24 h of reperfusion. Results The rectal temperature and HR were significantly increased, while RR was significantly decreased duing cerebral I/R.The neurological deficit score was significantly higher, cerebral infarct volume and the number of apoptotic neurons were significantly larger in the other groups than in group S. Emulsified isoflurane preconditioning reduced neurological deficit scores, cerebral infarct volume and the number of apoptotic neurons dose-dependently. Conclusion Emulsified isoflurane preconditioning can reduce focal cerebral I/R injury in a dose-dependent manner in rats.