外源性細胞色素C對膿毒癥小鼠心肌TGF-β1和Smad1/5/8影響的實驗研究

摘要： 目的探討外源性細胞色素c(Cytc)對膿毒癥小鼠心肌TGF-β1和Smad1/5/8的作用及影響。方法雄性昆明小鼠78只,隨機分為假手術組(Sham)、膿毒癥組(CLP)、細胞色素C處理組(T)。CLP組和T組用盲腸結扎穿孔法造模,Sham組僅開腹翻動盲腸。24 h造模成功后,T組經(jīng)尾靜脈注射外源性Cytc(20mg/kg)、Sham組和CLP組分別經(jīng)尾靜脈注射150(1生理鹽水。30 min后以0、6 h、12 h點取材,每個時間點5只小鼠,測左心室收縮壓(LV S1P)、左心室舒張末期壓(LVEDP)、左室內(nèi)壓力變化最大上升和下降速率(LV±dp/dt-max);取心肌組織分別做組織學檢查、RT-PCR和Western-Blot檢測TGF-β1和Smad1/5/8蛋白的表達;24h點留取電鏡標本,余下的小鼠觀察生存率。結果與CLP組比較,T組一般情況好轉,生存率提高,病理學改善;LVSP、LVEDP和LV±dp/dt-max提高(P<0.05);各組TGF-β1和Smad1/5/8蛋白均有表達,CLP組表達明顯增加,經(jīng)外源性Cytc干預后蛋白表達減少,CLP組與其它組比較差別有統(tǒng)計學意義(P<0.05)。結論外源性Cytc逆轉膿毒癥小鼠心肌線粒體功能抑制和心肌抑制,改善心功能。
Objective To explore the effect of exogenous cytochrome c upon the TGF-β1 and Smadl/5/8 of mice myocardium in the sepsis,reverse sepsis associated cardiomyocyte mitochondria function inhibition and myocardium depression,enhance cardiac function.Methods 78 male kunming rats were randomly divided into sham group(Sham),sepsis group(CLP) and exogenous cytochrome C treatment group(T). Cecal ligationand puncture was used to reproduce rat sepsis model on the CLP group and group T,Sham group was opened abdomen and flipped appendix.24 hours after operation,group T and Sham group and CLP group were respectively injected exogenous Cytc(20mg/kg) and 150μl saline via tail vein.30min after injection,all rats were evaluated at 0,6,12 hours.Each time point there were five rats,myocardium was done histopathological examination,RT-PCR and Western-Blot experiments,detected the content of TGF-β1 and Smadl/5/8 protein; At 24h time point,heart tissues each group were detected by transmission electron microscope.Rest rats were observed the survival rate.Results Compared with the CLP group,The general situation of group T improved and the survival rates generally increased,pathological changes improved;LVSP,LVEDP and LV±dp/dt-max increased(P < 0.05);RT-PCR and Western-Blot Detected that TGF-β1 and Smadl/5/8 protein of the myocardial tissue were expressed.Protein expression of CLP group significantly increased.Group T intervened by exogenous Cytc protein expression decreased.Compared with the other groups,the difference was statistically significant(P < 0.05).Conclusion Exogenous Cytc could reverse sepsis associated cardiomyocyte mitochondria function inhibition and myocardial depression and improve cardiac function.