外源性肾上腺髓质素对缺氧缺血再灌注脑损伤新生大鼠血浆及脑组织谷胱甘肽表达的影响

Effect of Exogenous Adrenomedullin on the Glutathion Levels of Plasma and Brain Tissue in Neonatal Rat with Hypoxic-Ischemia Reperfusion Brain Damage

目的探讨外源性肾上腺髓质素(ADM)对缺氧缺血再灌注脑损伤(HIRBD)新生大鼠血浆及脑组织谷胱甘肽(GSH)表达的影响。方法7日龄SD新生大鼠56只分为4组:正常对照组(不予任何处理)8只,HIRBD组(缺氧2 h、缺血1 h制成的模型)、预处理组(造模前0.5 h腹腔注入ADM0.1 mg/kg,余同HIRBD组)、治疗组(造模后立即腹腔注入ADM0.1mg/kg,余同HIRBD组)各16只。各组大鼠分别于再灌注后4、24 h断头取血、取脑,比色法检测GSH水平。同时在光学显微镜下观察另一侧脑组织的病理变化。采用SPSS11.5软件进行统计学分析。结果HIRBD组再灌注后24 h与4 h比较,病变面积扩大,同时由再灌注4 h的点状变性或坏死转变为再灌注24 h的片状或弥散性变性或坏死。再灌注后4 h和24 h HIRBD组血浆及脑组织中GSH水平较正常对照组显著降低(Pa<0.05),同时脑组织的病理评分较正常对照组显著增加(Pa<0.01)。再灌注后4 h和24 h预处理组和治疗组血浆及脑组织中GSH水平较HIRBD组显著增加(Pa<0.05),与正常对照组比较差异无显著差异(Pa>0.05),预处理组和治疗组之间比较无显著差异(P>0.05)。再灌注后4 h和24 h预处理组和治疗组脑组织病理评分较HIRBD组显著降低(Pa<0.01),预处理组和治疗组之间比较无显著差异(P>0.05)。结论外源性ADM可通过调节GSH的生成对新生大鼠HIRBD发挥保护作用。

Objective To explore the effect of exogenous adrenomedullin （ ADM ） on expressions of glutathion in plasma and brain tissue inneonatal rats with hypoxic - ischemia reperfusion brain damage （HIRBD） and the mechanism of action. Methods Fifty - six cases of 7 d SD rats were randomly divided into 4 groups including normal control group （without any treatment）, HIRBD group （the model with hypoxia for 2 h and iseheraia for 1 h） ,primed group （ abdomen infusion of ADM at 0.5 h before making model, the other was same to the HIRBD group） and treatment group （abdomen infusion of ADM at onces after making model, the other was same to the HIRBD group ）. The neonatal rats in 4 groups were derived blood and brain tissue after decapitation at either 4 h or 24 h after reperfusion. The levels of gtutathion （ GSH ） in plasma and brain tissue were determined by using chromatometry. Results In HIRBD group, the affection areas at 24 h after reperfusion enlarged compared with those at 4 h after reperfusion. Meanwhile ,the affection of punctiform degeneration or necrosis at 4 h after reperfusion transformed into the affection of lamellar or diffuse degeneration or necrosis at 24 h after reperfusion. The levels of GSH in plasma and brain tissue in HIRBD group at either 4 h or 24 h after reperfusion were significantly lower than that in normal control group （P. 〈0.05 ）. Meanwhile, the pathology score of brain section in HIRBD group was significantly higher than that in normal control group at either 4 h or 24 h after reperfusion（ Pa 〈0.01 ） and the damage of brain aggravated. The levels of GSH plasma and brain tissue in primed group and treatment group were significantly higher than those in HIRBD group at either 4 h or 24 h after reperfusion （Pa〈 0.05 ）. There were no significant differences compared with normal control group and between the primed group and treatment group （Pa〉 0.05 ）. Meanwhile the pathology score of brain section in primed group and treatment group were significantly lower than that in HIRBD group at either 4 h or 24 h after reperfusion（ Pa 〈 0.01 ） and the damage of brain lessened. There was no significant differences between the primed group and treatment group （P 〉 0.05 ）. Conclusion Exogenous ADM can induce the neuroprotection in HIRBD by adjusting the expression of GSH.