急性脑损伤致心肌损害中心肌G蛋白表达的改变

摘要

Objective To test the effect of Gs-protein and Gq-protein on cardiac damage induced by acute brain injury,and the contribution ofβ1-ARB and 5-HT2A RB to G-protein.Methods The Wistar rat model of acute brain injury was built.The mRNA level of Gsαand Gqαwere evaluated with real time PCR,and the protein level of Gsαand Gqαwere detected by Western blotting assay.Results Compared with NORMgroup,the mRNA level of Gsαwas (92.6 ±24)%in SHAMgroup,(39.7 ±30)%in ABI group and (80.1 ± 1 2)% in BETA group,respectively.The mRNA level of Gsαwas significantly decreased in ABI group compared to SHAM group,but significantly increased in β1-ARB treated BETA group,and there is no difference of GsαmRNA level betweenβ1-ARB treated BETA and SHAM groups.Compared with NORM group,the protein level of Gqαwas (1 05 ±30)% in SHAM group,(1 1 0 ±1 4)% in ABI group and (1 07 ±23)% in BETA group.There was no statistical difference among three groups.Conclusion The mRNA and protein of Gsαwere significantly decreased after acute brain injury,which indicates the occurrence of myocardial damage induced by acute brain injury may be related to the inhibition in signal transduction pathway mediated Gs-protein.Gs-protein may be in the form of expression change involved in the occurrence of myocardial damage induced by acute brain injury.%目的：建立动物急性脑损伤（acute brain injury，ABI）模型，观察心肌Gs 蛋白α亚基（αsubunite of Gs ，Gsα）和Gq 蛋白α亚基（αsubunite of Gq ，Gqα）的变化，探讨Gs 和Gq 在急性脑损伤致心肌损伤中的作用及其β1肾上腺素受体阻断剂（adrenalinβ1 receptor blocker，β1-ARB）和5－羟色胺受体2A阻断剂（5-hydroxytryptamine 2A receptor blocker，5-HT2ARB）对G蛋白的影响。方法复制Wistar大鼠ABI模型（n＝8）。采用数字表法随机分为正常组（NORM）、假手术对照组（SHAM）、急性脑损伤模型组（ABI）、β1-ARB组（BETA）和5-HT2A RB组（KETA组）。利用RT-PCR方法测定Gsα和GqαmRNA表达；通过Western blotting方法测定Gsα和Gqα蛋白表达。结果与正常对照组（NORM：100％）相比，SHAM组、ABI组和BETA组GsαmRNA表达分别为（92.6±24）％、（39.7±30）％和（80.1±12）％。ABI组GsαmRNA表达比SHAM组显著降低（P＜0.05），预先应用β1-ARB的BETA组GsαmRNA表达比ABI 组增高（P＜0.05），而与 SHAM组比差异无统计学意义（P＞0.05）；与正常对照组（NORM：100％）相比，SHAM组、ABI组和BETA组Gqα蛋白表达分别为（105±30）％、（110±14）％和（107±23）％，各组之间Gqα蛋白表达差异无统计学意义（P＞0.05）。结论 ABI组GsαmRNA和Gsα蛋白表达水平于脑损伤后显著降低。提示急性脑损伤致心肌损伤的发生可能与抑制Gs 蛋白介导的信号转导通路有关，Gs 蛋白可能以Gsα蛋白表达量改变的方式参与了急性脑损伤致心肌损伤的发生过程。