血糖升高水平对大鼠低血糖性脑损伤的影响

Influence of increased blood glucose level on brain injury after hypoglycemia in rats

目的探讨胰岛素诱导大鼠低血糖后，血糖升高水平对大鼠低血糖性脑损害的影响。方法30只Wistar4月龄雄性大鼠，体重（300±50）g，用简单随机抽样方法分为实验组（20只）、正常血糖对照组（A组，5只）和空白对照组（B组，5只）。实验组根据血糖再灌注水平分为1〈血糖≤3mmol／L组（C组）、3〈血糖≤6mmo]／L组（D组）、6〈血糖49mmol／L组（E组）、血糖〉9mmol／L组（F组），每组5只。采用TUNEL染色观察大鼠海马神经元凋亡，Fluoro—JadeB（FJB）染色观察神经元轴突和胞体的退变。染色组问计量资料采用单因素方差分析。结果（1）TUNEL染色：与A组及B组相比（海马CAl区：3．2±1．9、2．8±0．8；海马DG区：4．1±2．4、3．4±1．2），C组、D组、E组、F组海马凋亡细胞数（海马CAl区：40．2±3．1、38．7±2．4、36．8±2．6和76．4±6．3；海马DG区：62．4±4．2、59．8±3．7、68．1±2．8和125．4±5．8）凋亡细胞数增多，差异有统计学意义（海马CAl区：F=13．52，P〈0．05；海马DG区：F=14．29，P〈0．05）；F组（海马CAl区：76．4±6．3；海马DG区：125．4±5．8）大鼠海马凋亡神经元数目比C组、D组、E组（分别为海马CAl区：40．2±3．1、38．7±2．4、36．8±2．6；海马DG区：62．4±4．2、59．8±3．7、68．1±2．8）显著增多，差异有统计学意义（海马CAl区：F：5．08，P〈0．05；海马DG区：F=6．52，P〈0．05）；（2）FJB染色：与A组及B组相比，C组、D组、E组、F组海马退变神经元数目显著增多，差异有统计学意义（海马CAl区：F=18．49，P〈0．05；海马DG区：F=11．37，P〈0．05）；F组大鼠海马轴突退变神经元数目比C组、D组、E组显著增多，差异有统计学意义（海马CAl区：F=7．83，P〈0．05；海马DG区：F=14．29，P〈0．05）。结论在同一低血糖水平且持续时间相同的情况下，大鼠脑损害程度与低血糖后血糖升高水平有关：血糖升高水平过高，脑损害明显。

Objective To explore the influence of the rising blood glucose level on brain injury in rats after insulin-induced hypoglycemia. Methods A total of 30 Wistar rats （ weight ： （ 300 ± 50 ） g, age ： 4 months） were simpling randomly divided into three equal groups： experimental group （20 rats ）, both vehicle control group （ group A, 5 rats） and normal control group （ group B,5 rats）. According to the blood glucose concentration after reperfusion, 20 rats from the experimental group were sub-divided into four groups ： 1 〈 blood sugar ≤ 3 mmol/L （ group C, 5 rats ） , 3 mmol/L 〈 blood sugar≤ 6 mmol/L （ group D, 5 rats）,6 mmol/L 〈 blood sugar ≤9 mmol/L（ group E, 5 rats）, blood sugar 〉 9 mmoL/L （group F, 5 rats） （blood sugar = blood glucose level）. TUNEL staining was used to detect the neurons undergoing apoptosis, and Fluoro-Jade （ FJB ） staining was performed to reveal the degenerating neuronal cell bodies and axons. SAS 8.0 software analysis and processing, staining between the two groups of measurement data using single factor analysis of variance data. Results （ 1 ） TUNEL staining ： the percentage of apoptotic neurons showed an obvious increase from C, D, E, and F group （hippoeampal CA1：40. 2 ± 3. 1,38.7 ± 2. 4,36. 8±2. 6 and76. 4 ± 6. 3 ; hippocampal DG ： 62. 4 ± 4. 2,59.8 ± 3.7,68.1 ± 2. 8 and 125.4 ± 5.8 ） compared to group A and group B （ hippocampal CA1 ： 3.2 ± 1.9,2.8 ± 0. 8; hippocampal DG： 4. 1 ± 2.4,3.4 ± 1.2） , the difference was statistically significant （ hippoeampal CA1 ： F = 13.52, P 〈 0. 05 ; hippocampal DG ： F = 14. 29, P 〈 0. 05 ） ; among the subgroups from the experimental group, the percentage of apoptotic neurons from group F （ hippocampal CA1 ： 76. 4 -＋ 6. 3, hippocampal DG ： 125.4 ± 5.8 ） rose more markedly than the other three groups （ group C, D, E, hippocampal CA1：40. 2 ± 3.1,38.7 ± 2.4,36. 8 ± 2. 6 ; hippocampal DG ： 62.4 ± 4. 2,59. 8 ± 3.7,68. 1 ± 2. 8 ） , the difference was statistically significant （ hippoeampal CAI ： F = 5.08, P 〈 0. 05 ; hippocampal DG ： F = 6. 52,P 〈 0. 05 ）. （2） FJB staining ： there was a statistical significance between group A, B and group C, D, E, F （ hippocampal CA1 ： F = 18.49,P 〈 0. 05 ; hippocampal DG ： F = 11.37,P 〈 0. 05） ; furthermore, compared with group C, D, E, the percentage of FJB positive cells in group F was significantly increased. , the difference was statistically hippocampal DG：F = 14. 29,P 〈 0. 05）. Conclusion significant （ hippocampal CA1 ： F = 7. 83, P 〈 0. 05 ; Control the rats on the same level of blood glucose and the same duration of the hypoglycemia, the severity of brain injury is closely correlated to the rising blood glucose concentration after hypoglycemia： the higher glucose level is, the more serious imparement brain suffer.