Research On The Role Of Shenfu Injection Improves Sepsis-induced Myocardial Dysfunction Based On CaMKⅡ/MPTP Pathway

Background Sepsis is a life-threatening organ dysfunction caused by the body’s dysfunctional response to infection.It has a high mortality rate in intensive-care unit and is usually contribute to poor prognosis.Among them,sepsis-induced myocardial dysfunction is the main organ injury,usually occurs in the early stage of the disease,can seriously affect the prognosis of the disease.Objective Research of the protective effect of shenfu injection on rats with sepsis-induced myocardial dysfunction,and the changes of calcium/calmodulin-dependent protein kinaseⅡand mitochondrial permeability transition pore in the process of myocardial protection were researched to explore their mechanism of action.Methods（1）Sepsis model establishment and grouping:healthy male SD rats（240±10 g）were randomly divided into sham operation group（Sham）,cecal ligation and puncture model group（CLP）,low dose shenfu injection group（4 ml/kg,LSF）,high dose shenfu injection group（10 ml/kg,HSF）,16 in each group.（2）The severity of sepsis-induced myocardial dysfunction in rats:sepsis score was used to judge the severity and survival analysis was performed.（3）Cardiac function observation:36 hours after operation to check cardiac function by echocardiography.Serum cardiac troponin I and b-type natriuretic peptide were detected by enzyme-linked immunosorbent assay.（4）Infection in rats:36 hours after operation,the abdominal cavity was dissected to observe the infection,and the levels of IL-6,IL-10 and tumor necrosis factor-αwere measured.（5）Changes in myocardial tissue:HE staining to observe myocardial injury in rats with sepsis.（6）The mechanism of Shenfu injection in regulating mitochondrial permeability transition pore:the content of sarcoplasmic reticulum Ca²⁺ATPase in rat heart was measured by Elisa;the expression of Ca MKⅡ-δand MCU was detected by western blotting.At the same time,the myocardial mitochondria of each group were extracted,and The mitochondrial swelling method was used to detect the openness of the mitochondrial permeability transition pore of cardiomyocytes.Results（1）Sepsis score in CLP Group was higher than that in Sham group（P<0.05）,LSF and HSF scores were lower than that in CLP group（P<0.05）,and HSF score was lower than that in LSF group（P<0.05）.The survival rate of rats in the Sham group after operation was 100%,compared with the Sham group,the survival rate of the CLP group decreased（P<0.05）,the survival rate of the HSF group increased compared with the CLP group（P<0.05）,and the survival rate of the LSH group compared with the CLP group did not change significantly（P>0.05）.（2）Compared with the Sham group,SV and LVEF decreased in the CLP group（P<0.05）,and the SV and LVEF in LSH group and HSF group were higher than that in the CLP group（P<0.05）.The results of ELISA 36 hours after operation in each group showed that the serum BNP level of rats in the CLP group,LSF group and HSF group was higher than that in the Sham group（P<0.05）,but the serum BNP level of rats in the LSF group and HSF group was lower than that in the CLP group（P<0.05）,and the serum BNP level in the HSF group was lower than that in the LSF group（P<0.05）.Compared with the Sham group,serum c Tn I was increased in the CLP group（P<0.05）,and the index of HSF group decreased compared with that in the CLP group（P<0.05）.The results of HE staining of heart tissue showed that the myocardial fibers of the rats in the Sham group were closely arranged and regular,and the cell morphology was normal and the structure was clear.The arrangement of myocardial fibers in rats in the CLP group was disordered or even interrupted,myocardial cells were edema,and inflammatory cell exudation was visible;The arrangement of myocardial fibers in the LSF group and the HSF group was slightly disordered,the exudation of inflammatory cells was reduced,and the cell edema was reduced compared with that in the CLP group.（3）The serum IL-6 level of rats in the CLP group,LSF group and HSF group was higher than that in the Sham group（P<0.05）,IL-10 was lower than that in the Sham group（P<0.05）,the serum IL-6 level in the LSF group and HSF group was lower than that in the CLP group（P<0.05）,and IL-10 was higher than that in the CLP group（P<0.05）.Compared with the Sham group,serum TNF-αwas increased in the CLP group（P<0.05）,the HSF group decreased compared with the CLP group（P<0.05）,and the serum TNF-αlevel in the HSF group was lower than that in the LSF group（P<0.05）.（4）Compared with the Sham group,the content of SERCA in the CLP group decreased（P<0.05）,and compared with the CLP group,the content of SERCA in both the LSF group and the HSF group increased（P<0.05）.The results of Western blot showed that compared with the Sham group,the expression of Ca MKII in the CLP group increased（P<0.05）,the expression of CAMKII in the LSF group and HSF group decreased compared with the CLP group（P<0.05）,and the HSF group improved significantly compared with the LSF group（P<0.05）.Compared with the Sham group,the expression of MCU in the CLP group,LSH group and HSF group was increased（P<0.05）,and the expression of MCU in the LSH group and HSF group was not significantly changed compared with that in the CLP group（P>0.05）.Conclusion The shenfu injection can improve myocardial injury in sepsis,and its mechanism may be associated with inhibiting the expression of Ca MKII and regulating the abnormal opening of MPTP.