肺组织β-AR和GRK2与重症急性胰腺炎肺损伤的关系以及甲强龙的影响

目的：探讨重症急性胰腺炎（SAP）致急性肺损伤（ALI）大鼠肺组织β-AR和G蛋白偶联受体激酶2（GRK2）的变化规律以及甲强龙的影响。方法：SD大鼠36只，随机分为3组，每组12只。对照组，仅做十二指肠翻动；模型组，胰胆管逆行注射5%牛磺胆酸钠（1 mL/kg），建立SAP模型；干预组，建立SAP模型后1 h给予甲强龙（30 mg/kg）。于6 h和12 h分别处死大鼠6只取肺组织，放射配基结合实验测量肺组织β-AR最大结合容量B_max和平衡解离常数K_d，免疫荧光法检测肺组织GRK2表达。结果：模型组和干预组胰腺组织损伤评分显著高于对照组，模型制备成功；模型组和干预组肺组织损伤评分显著高于对照组，发生SAP肺损伤；模型组β-AR B_max显著低于对照组和干预组，K_d显著高于对照组和干预组；模型组GRK2的表达显著高于对照组和干预组。结论：SD大鼠肺组织有丰富的GRK2表达，SAP肺损伤大鼠肺组织GRK2表达显著增加，这可能是β-AR下调的重要机制。

Relationships of β-AR and GRK2 in lung,lung injury in rats with severe acute pancreatitis and therapeutic effect by methlyprednisolone

AIM: To investigate the variation of β-AR in pulmonary microvascular endothelial cells and variation of GRK2 in lung and to explore the therapeutic effect of methlyprednisolone in severe acute pancreatitis-associated lung injury model in rats.METHODS: 36 rats were divided into three groups randomly: the control group,the experimental group,and the intervention group.In the experimental group,severe acute pancreatitis-associated lung injury model was induced in SD rats by retrograde injection of 5% sodium taurocholate into biliopancreatic duct.In the control group,laparotomy was performed,duodenum and pancreas were flipped only.In the intervention group,methlyprednisolone (30 mg/kg) was injected into rump muscle of rats after model developed.At 6 and 12 h after model was developed,the maximum binding capacity (B_max) and the K_d value of β-AR were detected in lung by means of radioactive ligand binding assay.GRK2 expression was detected in lung by means of immunofluorescence.RESULTS: The scores of the severity of pancreatitis and the severity of lung injury in the experimental group were obviously higher than those in control group.In the experimental group,Bmax was obviously lower,K_d and GRK2 were obviously higher than those in control group and the intervention group.CONCLUSION: The β-AR in lung is lower down and GRK2 expression in lung is up-regulated in severe acute pancreatitis-associated lung injury model in rats.The therapeutic effect of methlyprednisolone to severe acute pancreatitis-associated lung injury is positive.