颈交感神经阻滞对糖尿病大鼠脑线粒体功能的影响

目的 观察颈交感神经阻滞对糖尿病大鼠脑线粒体功能的影响.方法 雄性成年大鼠40只随机分为3组:对照组(n=l0,腹腔注射注射等量缓冲液),糖尿病组(n=15,采用STZ糖尿病模型按65 mg/kg剂量腹腔1次注射1％ STZ制备糖尿病大鼠),糖尿病+颈交感神经阻滞组(n=15,按65 mg/kg剂量腹腔1次注射1％ STZ,糖尿病成模后8周给予颈交感神经阻滞治疗).造模后12周水迷宫实验观察各组大鼠的认知功能.并于12周处死大鼠,采用Clark氧电极法测定大鼠海马线粒体的呼吸功能,免疫组化检测海马IL-6、TNF-α的表达.结果 造模后12周,糖尿病组存活12只,阻滞组存活13只.糖尿病组、阻滞组与对照组相比,逃避潜伏期明显延长、穿越平台的次数明显减少(P＜0.05).糖尿病组线粒体呼吸功能为R3(28.51±3.01)、R4(13.93 ±1.16)、RCR(2.09±0.27),阻滞组的为R3(45.26±4.21)、R4(11.99±1.11)、RCR(3.52±0.32),对照组为R3 (66.31 ±5.65)、R4(12.97±3.38)、RCR (4.78 ±0.68),糖尿病组和阻滞组线粒体呼吸功能均较对照组组明显下降,主要表现为R3和RCR值显著降低(P＜0.05);但阻滞组的R3和RCR高于糖尿病组(P＜0.05).在海马CA1区,糖尿病组IL-6、TNF-α表达为(53.32 ±6.29)、(63.21±13.24),阻滞组为(28.14±3.82)、(32.76±5.98),均高于对照组(13.87 ±2.54)、(11.09±8.87) (P ＜0.05).阻滞组明显低于糖尿病组,差异有统计学意义(P＜0.05).结论 颈交感神经阻滞可改善糖尿病大鼠脑线粒体功能,其机制可能与其下调IL-6、TNF-α有关.

Effect of cervical sympathetic ganglia block on hippocampal mitochondria in diabetic rats

Objective To determine the effect of cervical sympathetic ganglia block on hippocampal mitochondria respiratory function in diabetic rats.Methods A total of 40 male adult rats were randomly divided into 3 groups:control (n =10),diabetes (n =15),and diabetes + cervical sympathetic ganglia block group (n =15,block group).After the rat model of diabetes were established by intra-peritoneal injection of 1％ STZ at a dose of 65 mg/kg,and cervical sympathetic ganglia block was carried out in 8 weeks after model establishment.Water maze test was used to observe the cognitive function in rats in 12 weeks after model establishment.Then the rats were sacrificed at 12 weeks,and the hippocampal mitochondria respiratory function was observed by Clark oxygen electrode,and the expression levels of IL-6 and TNF-α were determined by immunohistochemical assay.Results At 12 weeks after model establishment,there were 12 mice in the diabetes group and 13 in the block group.The escape latency was significantly extended and the number of crossing the platform was obviously reduced in diabetic group and cervical group when compared with control group (P ＜ 0.05).Respiratory state 3 (R3),R4,and respiratory control rate (RCR) were 45.26 ±4.21,11.99 ± 1.11 and 3.52 ±0.32,respectively in the diabetic group,and were 66.31 ±5.65,12.97 ± 3.38 and 4.78 ±0.68,respectively in the control group.The mitochondrial respiratory function were significantly lower in the diabetic group and block group than the control group,mainly with significantly decreased R3 and RCR (P ＜0.05).But R3 and RCR were significantly higher in the block group than the diabetic group (P ＜0.05).In the CA1 region of the hippocampus,the expression levels of IL-6 and TNF-α were 53.32 ±6.29 and 63.21 ± 13.24 in the diabetic group,and 28.14 ± 3.82 and 32.76 ± 5.98 in the block group,and the levels were obviously higher in the both groups than the control group (13.87 ± 2.54,11.09 ± 8.87,P ＜ 0.05).But the levels in the block group was significantly lower than those in the diabetic group (P ＜ 0.05).Conclusion Cervical sympathetic ganglia improves brain mitochondrial function in diabetic rats,which may be associated with its down-regulating IL-6 and TNF-α.