| Heart failure is a serious clinical syndrome,which not only characterized by the decline of cardiac pump function,but also accompanied with the damage of kidney,lung,liver and other target organs.The heart rate decreases when heart failure occurs,accompanied with a reduction in renal blood flow and glomerular filtration rate,so that the redistribution of renal blood flow,resulting in renal damage.Renal function damage can not only lead to further aggravation of heart failure and reduce the therapeutic effect,but also increase the mortality rate.It can be seen that the two interact with each other to form a vicious cycle,and further accelerate the progress of heart failure.Ramipril(Ramipril,RAM)as an efficient ACEI vasodilator,as well as first-line drug in the treatment of heart failure,its mechanism in the protection of renal Public opinions are divergent still.This study is to investigate the effect of ramipril on renal cell apoptosis in rats with heart failure,through the detection of the expression levels of Bcl-2,Bax,Caspase-3 and CytC.Objective:The model of heart failure rat in the study was built by abdominal aortic constriction.Then,the model was given drug intervention,the morphological structure of kidney tissue in rats was observed by hematoxylin and eosin staining,TUNEL technique is used to describe profile of kidney tissue apoptosis,through SP assay and Western blot examining the expression of Bcl-2 protein,Bax protein,Caspase-3 protein and Cyt-C protein in the renal cells of rats with heart failure,RT-PCR method was used to measure the expression level of their mRNA in the kidney of rats.Through the observation of ramipril effect on renal cell apoptosis and apoptosis related factors,to explore the possible protective mechanism of the drug on renal tissue in rats with heart failure.Methods:1 40 male clean grade Wistar rats were selected.Chosen 10 rats as sham operation group randomly,the other rats were operated with abdominal aortic coarctation surgery.Left ventricular end diastolic pressure(LVEDP)was more than or equal to 15 mmHg means that the model was made successfully.At the same time,the rats in sham operation group were not ligated.The successful model of the 20 rats were assigned to model control group and ramipril group randomly.2 When rats in each group were at the end of the observation,monitor and record corresponding LVEDP of the rats accurately through the multi conductivity physiological recorder.After the laparotomy,rats were taken to weigh.3 HE staining was used to examine the morphological changes of renal tissue in each group.4 TUNEL method was used to detect the apoptosis of renal cells and calculate the apoptotic index(AI).5 SP and Western blot method were used to detect the protein expression of Bcl-2,Bax,Caspase-3 and Cyt-C in kidney tissue of each rat.6 RT-PCR method was used to evaluatet the mRNA expression of Bcl-2,Bax,Caspase-3 and Cyt-C in rats.Results:1 LVEDP results with all groupThe LVEDP of sham operation group,model group and ramipril group respectively were:(5.56±0.95)mmHg,(19.48±1.86)mmHg,(12.16±1.46)mmHg.Compared with the sham group,the LVEDP in model group and ramipril group increased obviously;the LVEDP of ramipril group was decreased compareed with model group(P<0.01).2 Pathological changes of renal tissue were observed by HE stainingIn the sham operation group,the cells of glomerular and renal tubular were morphologically normal,arranging in a regular and compact structure;the renal tubular structure in the model group was disordered,with epithelialcells arranged loosely and lumen dilated;renal tubular structure of the ramipril group also appeared structural disorder,cells arranged loosely,but without lumen expansion.3 The apoptotic index(AI)of renal cells in each group showed thatThe AI in sham operation group,model group and ramipril group were(2.51±0.97)%,(40.79±1.31)% and(19.89±1.24)%.the AI of model and ramipril group were significantly increased Compared with sham operation group(P<0.01);the AI in ramipril group was decreased obviously Compared with model group(P<0.01).4 The protein expression of Bcl-2 and Bax was detected by SP method in kidney tissue of each ratThe expression trend of Bcl-2 protein in each group was:in sham operation group,there was a lot of dark brown substance in the cells under the microscope,but model control group showd a little expression;Ramipril group was seen moderate expression,it was significantly less than the sham operation group,but higher than the model control group.The results showed:the expression of Bax protein had no obvious dark brown substance in rats cells in sham operation group;model group rats cells had obvious dark brown substance expression,while ramipril group in visible dark brown substance expression amount.5 The expression of Caspase-3 and Cyt-C protein were estimated by Western blot methodThe expression trend of Caspase-3 protein was similar to Cyt-C protein’s,compared with sham operation group,the expression level of Caspase-3 and Cyt-C in the other two groups were significantly higher(P<0.01);compared with model group,the ramipril group was obviously lower(P<0.01).6 The mRNA expression of Bcl-2,Bax,Caspase-3 and Cyt-C in kidney cells were evaluateted by RT-PCRThe expression of Bax,Caspase-3 and Cyt-C mRNA expression trend were similar,the expression level of them in model group were increasedsignifycantly compared with the sham group(P<0.01),but the expression level of Bcl-2 mRNA decreased(P<0.01);compared with model control group,the mRNA level expression of Bax,Caspase-3 and Cyt-C in ramipril with rats decreased significantly(P<0.01),while the expression level of Bcl-2 mRNA increased significantly(P<0.01).Results:1 The mechanism of renal damage in rats with congestive heart failure is closely related to the occurrence of apoptosis.2 Ramipril is able to depress renal cell apoptosis in rats with heart failure effectively,the protection mechanism might be related to the regulation of Bcl-2,Bax,Caspase-3 and Cyt-C,thereby blocking the blockade of mitochondrial pathway. |
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