谷氨酰胺诱导热休克蛋白的表达及对肺损伤的保护作用的研究

Glutamine induces heat shock protein70 and protects against ALI in the rat

目的通过利用谷氨酰胺(Gln)诱导大鼠热休克蛋白70(HSP70)表达以探讨HSP70对急性肺损伤的保护作用。方法雄性SD大鼠42只随机分成三组:O组为油酸损伤组(经尾静脉按25mL/kg量注入生理盐水后注入油酸);G组为干预组(经尾静脉按25mL/kg量注入3(Gln溶液后注入油酸);C组为正常对照组(经尾静脉注入等量生理盐水)。观察三组大鼠氧分压(P(O2))、肺湿/干重比值和髓过氧化物酶(MPO)、肺组织形态学变化、肺组织HSP70的表达以及血中Gln浓度的变化。结果 (1)肺组织和血MPO含量O组均较C组明显升高(P<0.01),G组与O组比较明显下降(P<0.01)。(2)肺组织湿/干比O组大鼠均高于C组(P<0.01),而G组与O组比较显著下降(P<0.01)。(3)O组动脉P(O2)与C组比较明显降低(P<0.01),G组则较O组明显升高(P<0.01),仍较C组低(P<0.01)。(4)Gln浓度O组与C组比较明显下降(P<0.05),G组明显高于O组(P<0.01)。(5)肺泡上皮细胞HSP70阳性细胞数O组较C组明显增高(P<0.01),G组与O组比较也明显增加(P<0.01)。病理切片结果显示O组呈明显肺损伤改变,G组病理改变较O组明显改善。结论 Gln能够明显地增加HSP70的表达并对急性肺损伤产生保护作用。

Objective Inducement of heat shock protein 70（HSP70） by glutamine to study the role of HSP70 in protection against ALI in rat.Methods 42 SD male rats were randomly divided into 3 groups which were infusion the oil acid after infusion physiology brine（25 mls/ kg） through the tail vein（O group）,infusion the oil acid after infusion 3% glutamine through the tail vein（G group）,and infusion the same quantitative physiology brine by the tail vein（C group）.Then rats in every group were killed alively and to be observed separately for the variety of P（O2）,MPO,wet/ dry rate,lung tissue pathology and expression of HSP70 and variety glutamine＇s density in blood.Results MPO levels in lung tissue and blood in group O that were compared with those in group C increased significantly after oil acid injection（P 0.01）.Compared with hat in group O,MPO levels in lung tissue and blood in group G dropped significantly（P 0.01）.Wet/ dry rate increased significantly in group O than those in group C（P0.01）.Wet/ dry rate decreased more in group G than those in group O（P 0.01）.P（O2） was lower in group O than that in group C（P 0.01）.P（O2） in group G went up obviously,as compared with those in group O（P 0.01）.But the levels of P（O2） in group G was still lower than those in groups C.Glutamine density in blood in group O was lower than that in group C after oil acid injection（P 0.05）,and dropped gradually.Glutamine density in group G was higher than that in group O.HSP70 in lung tissue in group O rose significantly（P0.01）.But those in group G went up more significantly than those in group O（P 0.01）.The variety of lung tissue pathology in group G was better than that in group O.Conclusion Glutamine could induce the expression of HSP70 and protect against oil acid ALI in rat.