The Protective Effect Of 3H-1,2-dithiole-3-thione On Sepsis-induced Myocardial Dysfunction

Objective:This article explores whether D3T plays a protective role in the sepsis-induced cardiomyopathy and whether it plays a role by regulating the Nrf₂ signaling pathway.Methods:In this experiment,a single intraperitoneal injection of LPS（5mg/kg）was used to build the rat sepsis-induced cardiomyopathy model.Forty-eight Sprague-Dawley rats were randomly divided into 6 groups（8 rats in each group）including:blank control group（CON group）,sepsis 6h group(LPS_6h group),sepsis 12h group(LPS_12h group),sepsis 24h group(LPS_24h group),sepsis 48h group(LPS_48h group)and D3T treatment group（D3T group）.The rats in D3T group were given 10mg/kg D3T 2 hours before the modeling,and all rats in LPS group were given same volume of DMSO.After modeling,the general state of the rats was observed.LPS_6h group,LPS_12h group,LPS_24h group and LPS_48h group were placed in the femoral artery indwelling needle and ventricular catheter respectively after modeling 6h,12h,24h,48h.D3T group and blank group were processed same as described before after modeling 12 hours.By electrophysiological recorderto,blood pressure,heart rate,left ventricular maximum contraction rate（dmax/t）and left ventricular end-diastolic pressure（LVEDP）were detected assess hemodynamics and cardiac function,then cardiac specimens were obtained after thoracotomy.Myocardial tissues from each group were stained with HE and observed histological changes.Myocardial tissue from each group were homogenized,meanwhile the levels of peroxide malondialdehyde（MDA）and superoxide dismutase（SOD）were detected and then assessed the change of oxidative stress level.Western blotting was used to detect the expression of Nrf2（intranuclear and cytoplasm）,HO-1 and NQO1 protein in myocardial tissue in CON,LPS12h and D3T groups.Real-time quantitative PCR was used to detect the mRNA level of HO-1 and NQO1 in myocardial tissues in CON,LPS12h and D3T groups.Result:1.Results of hemodynamics and cardiac function:Compared with the blank control group,heart rate and left ventricular end-diastolic pressure were increased in LPS groups,while blood pressure and left ventricular maximum contraction rate were decreased.The change of LPS_12h group was the most significant;Heart rate and left ventricular end-diastolic pressure of D3T treatment group were decreased than LPS_12h group,while blood pressure and left ventricular maximum contraction rate were increased,and the results were statistically significant（P<0.05）.2.The results of HE staining（200×）showed that the myocardial tissue of CON rats was clearly visible and neatly arranged,and no inflammatory cell infiltration was observed.The myocardial fibers were disordered in the rats of LPS sepsis,and the myocardial cells were edema and deformed.A large number of inflammatory cell infiltrates were observed in the LPS24h group.In the D3T group,the edema of the myocardial cells was reduced and the inflammatory cell infiltration was reduced compared with the LPS12h group.3.The results of oxidative stress test showed that:Compared with the blank control group,the MDA content of LPS sepsis groups was increased and the SOD content was decreased in the myocardial tissue of rats.The LPS12h group change significantly;As for D3T treatment group,the MDA content was decreased and the SOD content was increased significantly than LPS_12h group,the results were statistically significant（P<0.05）.4.Western blotting protein expression results showed that:The expression of nucleus of Nrf2,HO-1 and NQO1 in D3T treatment group were significantly increased than LPS12h group,the results were statistically significant（P<0.05）.And cytoplasmic Nrf2 expression was no significant change,the results were no difference（P<0.05）.5.Real-time quantitative PCR relative mRNA level results show that:The HO-1 and NQO1 genes in the D3T group were significantly higher than those in the LPS12h group,and the results were statistically significant（P<0.05）.Conclusion:1.D3T could protect sepsis-induced cardiomyopathy and relieve myocardial injury.2.It may play a protective role by regulating the expression of Nrf2,with the enhancing expression of downstream two phase detoxifying enzymes and antioxidant enzymes,which will causes oxidative stress reducing and inflammatory reaction inhibition in septic rats.