失血性休克大鼠心脏G蛋白变化及纳络酮对它的影响

Changes of the contents of G protein on hemorrhagic shock of rats and the effect of naloxone

目的 :研究失血致低血容量性休克大鼠心脏组织鸟苷酸结合蛋白 (Guanine nucleotide- binding protein,G蛋白 )含量的变化及纳络酮对其影响。方法 :颈总动脉放血 ,使平均动脉压降至 45 mm Hg(1mm Hg=0 .133k Pa) ,稳定 1h,完成失血致低血容量性休克大鼠模型 ,2 1只大鼠随机均分为 :休克组、纳络酮治疗组、空白对照组。采用Western blot技术测定大鼠休克后 6 h心脏组织中 Gsα,Giα,Gqα,Goα的含量。结果 :休克后心脏膜组织 Gsα两条带较对照组显著降低 (P<0 .0 5和 P<0 .0 1)。 Giα和 Gqα带较对照组则显著升高 (P<0 .0 1和 P<0 .0 5 ) ,Goα降低 (P<0 .0 5 )。纳络酮治疗后 ,Gsα两条带较休克组显著升高 (均 P<0 .0 1) ,Giα和 Gqα带较休克组显著降低 (P<0 .0 5 ;P<0 .0 1) ,Goα降低更明显 (P<0 .0 1)。结论 :大鼠心脏组织 G蛋白含量的变化可能参与了失血致低血容量性休克时信号转导系统障碍的发生。纳络酮在改善休克的同时 ,也改变了 G蛋白的水平 ,提示休克大鼠的心脏收缩舒张功能可能有 G蛋白参与。

AIM:To study the alteration of the content of guanine nucleotide binding protein α subunits(Gα protein) in myocardium during shock,and the effect of naloxone (NAL) on the G protein. METHODS:Hemorrhagic shock was performed in Wistar rats by carotid artery bleeding to maintain the mean arterial pressure (MAP) at 45 mm Hg (1 mm Hg=0.133 kPa) for one hour. Twenty one Wistar rats were randomly divided into three groups. Group 1 (NS, n =7),as control;Group 2 (HS n =7),shock control; Group 3(NAL, n =7),NAL+HS. Determining mean arterial pressure,then,the content of Gsα,Giα,Gqα,Goα in the sarcolemma were measured by Western blot analysis at 6 hours after shock. RESULTS:In the ventricles,the contents of two Gsα bands,one Goα band in the group HS were significantly lower than in the group NS, P <0.05, P <0.01 and P <0.05. But,the content of two Gsα bands in groups NAL were significantly higher than in the group HS, P <0.01; P <0.01. The content of one Goα band in the groups NAL was significantly lower than in the group HS, P <0.01. The content of one Giα band and Gqα band in the group Hs was significantly higher than in the group NS, P <0.01 and P <0.05. The lower in the conent of one Giα band and Gqα band were attenuated in the groups NAL as compared with the group HS. CONCLUSION:Alteration of content of G proteins in the ventricles may contribute to the dysfunction of adenyl cyclase signal transduction system during the hemorrhagic shock,NAL not only could improve hemorrhagic shock,but also could change the level of G protein.