Establishment And Metabolic Research Of Rat Model Of Cardiac Insufficiency Complicated With Diabetes Mellitus

Objective In order to meet the clinical diagnosis, intervention and treatment needs of related diseases, we established a rat model of cardiac insufficiency complicated with diabetes mellitus firstly, then use the UPLC-MS platform to analyze the metabolic profiles of the rats serum and myocardial tissue, the characteristic endogenous metabolites were selected and then the related metabolic pathways and pathological mechanism were discussed. Methods 70 male Specific Pathogen Free(SPF) rats were randomly divided into four groups: Normal, DM, AAC and AAC+DM group.First, rats of DM group were randomly divided into five subgroups: DM1~5 and treated with different doses of STZ respectively: 40,45,50,55,60mg/kg. Then establish the model of cardiac insufficiency with abdominal aortic constriction in AAC and AAC+DM group. After two months of constriction, the same methods like DM group were used in AAC+DM group. Observing the rats' dynamic changes of general condition and weight change during the process of experiment and monitoring the random blood glucose levels of 72 h and 4 weeks after STZ injection, evaluate the rats' echocardiograph and cardiac pathology changes after 1 month of STZ injection.Then collected serum and myocardial tissue samples of rats in each group, the principal component analysis(PCA) and orthogonal partial least squares discriminate analysis(OPLS-DA) model were constructed, variable importance in projection(VIP)and VIP confidence were used to select potential ions.Non-parametric test by SPSS 17.0(SPSS,USA)were used to exclude variables with p>0.05 from these selected potential metabolite ions, the ions were identified, then analyse the trend and metabolic pathway changes of different metabolites, and discussed its potential clinical value. Results Comparing different doses, the model was more stable when STZ is 45mg/kg, and the rats? blood glucose level,echocardiographic findings and myocardial tissue microscopic morphology were changed significantly which in line with the changes of cardiac dysfunction and diabetes mellitus. The OPLS-DA model of rat serum(R2X =53.5%, Q2 =6.2%/ R2X=44.7%, R2 Y =73.2%, Q2 =36.3%) and cardiac tissue(R2X =40.4%, Q2 =8.9%/R2 X =35.1%, R2 Y =32.5%, Q2 =13.3%)was successfully constructed which is goodenough to separate different ststus of disease. Finally, we identified 30 characteristic metabolites in serum, including LPC, LPA, bile acids, sphingomyelin, etc and we identified 10 characteristic metabolites in myocardial tissue, including LPC, LPA,dihydrouracil, and so on. Through the pathway analisis of serum, we find that glycerol phospholipid metabolism, sphingomyelin metabolism, glucuronic acid metabolic pathways are the main pathways but in the myocardial tissue, the main metabolic pathway is glycerol phospholipid metabolism. Conclusion Establishing the rat's model with the above method is simple, reliable and with high stability. At the same time, through the analysis of the rat's serum and tissue metabolic profile, we are fortunate to find many characteristic metabolites closely related to the occurrence and development of the diease. Compare with Normal group, these characteristic serum metabolites such as Adrenic acid, cholic acid, LPC, LPA, palmitic acid,prostaglandins, sphingosine, carnitine was significantly higher in AAC+DM group,but D-glucose has a decline which showed a significant statistical difference(p<0.05).In metabolites of myocardial tissue, we found that the level of LPC, LPA,dihydrouracil were lower excpt Galactinol in AAC+DM group than Normal group,which also showed significant statistical difference(p<0.05).Although the LPC and LPA are both involved in serum and myocardial tissue metabolism, they showed different content levels, we speculate that the LPC and LPA were not produced by myocardial tissue but other organs or tissue which plays a biological role in cardiac tissue through the blood circulation. Through the metaboanalist, we find that glycerol phospholipid metabolism, sphingomyelin metabolism, glucuronic acid metabolic pathways plays a important role in the status of cardiac insufficiency complicated with diabetes mellitus. Among them, glycerol phospholipid metabolism is the main metabolic pathways which appeared in serum and myocardial tissue simultaneously and involved a variety of mechanisms, including oxidative stress, membrane disruption, shift of energy metabolism, insulin resistance and so on.