持续低血糖新生大鼠大脑基质金属蛋白酶-2活性和氧化型谷胱甘肽水平的变化  

Changes of cerebral matrix metalloproteinase-2 activity and oxidative glutathione level in newborn rats with persistent hypoglycemia

作　　者：刘江勤[1] 陈超[2] 郭佳林[1] 姚明珠[1] 陆国强[1] 

机构地区：[1]同济大学附属第一妇婴保健院新生儿科,上海200040 [2]复旦大学儿科医院新生儿科

出　　处：《中华围产医学杂志》2012年第1期25-29,共5页Chinese Journal of Perinatal Medicine

摘　　要：目的 研究7日龄新生大鼠持续低血糖对脑组织氧化应激和基质金属蛋白酶2（matrixmetalloproteinase-2，MMP-2）水平的影响，探讨低血糖引起新生儿脑损伤的机制。方法7日龄大鼠皮下注射普通胰岛素诱导持续性低血糖（n=6），观察36h后收集脑皮质、海马和丘脑组织，采用谷胱甘肽活性测定试剂盒测定总谷胱甘肽（glutathione，GSH）和氧化型GSH（glutathionedisulfide，GSSG）含量，计算GSSG／GSH，并采用酶谱法测定MMP-2活性。设正常血糖对照组6只。统计学方法采用t检验、双因素方差分析、单因素方差分析或Pearson相关性分析。结果持续低血糖36h后，低血糖组脑组织总GSSG含量较对照组增高约1．5倍[（15．89±5．46）mg／g蛋白与（6．15±3．42）mg／g蛋白，t=3．704，P=0．004]。GSSG／GSH比率也显著高于对照组[（5．58±1．79）％与（2．79±1．76）％，t=2．712，p=0．022）]。低血糖组与对照组比较，大脑皮质和海马部位的GssG／GsH比率差异无统计学意义，而丘脑GSSG含量和GSSG／GSH比率显著高于对照组GSSG：（15．93±5．75）mg／g蛋白与（5．03±5．14）mg／g蛋白，P〈0．05；GSSG／GsH：（6．50±3．25）％与（2．41±3．12）％，P〈0．05]。低血糖组脑组织MMP-2总活性较对照组显著增高（2．22±0．59与1．21±0．17，t=4．064，P=0．002）。低血糖组与对照组脑组织不同部位比较，MMP2活性均显著增高（皮质：2．14±0．51与1．17±0．27；海马：2．31±0．72与1．22±0．37；丘脑：2．22±0．68与1．24±0．18；三者P均〈0．01）。脑组织MMP-2活性与GSSG的含量和GSSG／GSH比率分别呈正相关（r=0．575和0．484，P-0．0002和0．0003）。结论氧化应激是7日龄新生大鼠持续低血糖造成脑损伤的重要机制，其相关部位主要为丘脑。低血糖可使脑组织MMP-2活性升高，与GSSG和GsSG／GSH的含量有关。Objective To investigate the effect of persistent hypoglycemia on the cerebral oxidative stress and matrix metalloproteinase-2 （MMP-2） activity of newborn rats and to explore the potential mechanism of hypoglycemia-induced brain injury of newborn. Methods Seven-day-old rats were injected insulin subcutaneously to induce persistent hypoglycemia. Cerebral cortex, hippocampus and thalamus were collected after 36 hours＇ observation and stored in -80℃. Glutathione （GSH） and glutathione disulfide （GSSG） were detected by commercial kit and GSSG/GSH was calculated. MMP-2 activity was detected by gelatin zymography. The data were analyzed by t test, one or two-way analysis of variance and Pearson correlation analysis. Six rats were set as the normal glucose group. Results Thirty-six hours after induction of hypoglycemia, the cerebral GSSG and GSSG/GSH of hypoglycemic pups elevated about 1.5 times higher than those of control group [GSSG： （15. 89±5.46） vs （6.15±3.42） mg/g protein, t=3. 704, P=0.004; GSSG/GSH： （5.58±1.79） % vs （2.79±1.76） %, t=2. 712, P=0. 022]. The GSSG and GSSG/GSH in thalamus of hypoglycemia were significantly higher than those of control [GSSG： （15.93±5.75） mg/g protein vs （5.03±5.14）mg/g protein, P〈0.05; GSSG/GSH： （6.50±3.25）% vs （2.41±3.12） %,P〈0. 05], whereas there were no significant differenees in the cortex and hippocampus. The total MMP 2 activity of hypoglycemic animals （2.22±0.59） was significantly higher than that of control （1.21±0. 17）（t=4. 064, P=0. 002）, and signifieant differences were found between the two groups in cortex （2. 14±0.5 vs 1.17±0.27）, hippocampus （2.31±0.72 vs 1.22±0.37） and thalamus （2.22±0. 68 vs 1.24＋0. 18） with all P〈0.011. The activity of MMP 2 was positively related to GSSG （r=0.575, P 0.0002） and GSSG/GSH （r=0,484, P=0.0003）. Conclusions Oxidative stress might play an important role in the persistent hypoglycemia induced brain injury of 7-day-old rat pups an

关 键 词：婴儿持续高胰岛素血症性低血糖症 基质金属蛋白酶2 谷胱甘肽 谷胱甘肽二硫化物 大鼠 

分 类 号：R722.1[医药卫生—儿科]