| Objective:The incidence of diabetic cardiomyopathy is becoming higher and higher, and myocardial apoptosis is closely related with diabetic cardiomyopathy. Apoptosis has three main channels: death receptor mediated exogenous approach, the endogenous way mediated by mitochondria, ERS (endoplasmic reticulum stress) mediated pathway. There are more researches about the first two pathways, so the third way is the focus of current research. To research the mechanism of ERS mediated apoptosis can provide a new direction for Chinese medicine preventing and treating diabetic cardiomyopathy.To explore the pathogenesis related ERS in the course of the diabetic cardiomyopathy, to observe the apoptosis of myocardial cells and to explore the therapeutic effect and mechanism of the astragalus and puerarin combination toward diabetic cardiomyopathy and whether to reduce the effect of myocardial cell apoptosis via the main factors related ERS were our aims in the all experiment.Methods:C57BL/6J mice were used as control called the normal group, the diabetic KKAy mice were randomly divided into the model group and the treatment group by random fasting blood glucose. Each group had 30 mice. The normal group was with daily intraperitoneal injection of the same volume saline as the treatment group(4.3ml/kg). The model group and the treatment group were with high fat feed, daily separated intraperitoneal injection of astragalus membranaceus injection (3ml/kg) and puerarin injection (1.3ml/kg). At 20th week, 24th week,28th week,10 mice of each group were executed, picked the eye and taked on lml blood, to detect the fasting blood glucose, serum triglyceride, total cholesterol. At the same time, the heart tissue were taken, part of the fixed for observation the structure of the hreart, the rest of the cryopreserved tissue for the testes of mRNA and protein expression.Results:(1) At 20th,24th,28th week, fasting blood glucose, triglyceride and total cholesterol of the model group were higher than that of the normal group, with statistical significance; There was a significant rise in the treatment group than the model group, with statistical significance at 20th week and 24th week; There was no obvious significance at 28th week.(2) HE staining showed that at 20th week,24th week,28th week, the structure of myocardial cells in normal mice was neat, complete and clear. The model group cardiomyocytes contracted, cytoplasm dissolved, cellular structure damage, seedless. The treatment group myocardial cells were mild atrophy.(3) Masson staining showed that normal group of myocardial cells mixed with a little collagen fiber. Cells arranged well without absence and morphological changes. The Model group of myocardial extracellular matrix contained a lot of collagen accumulation. Collagen fibers in the treatment group compared with model group significantly reduced.(4) Transmission electron microscopy showed that the structure of the mitochondria and endoplasmic reticulum was clear and complete in the normal group. In the model group, the myocardial cell cytoplasm osteoporosis, endoplasmic reticulum and the nucleus were swelling. The mitochondria swelling and cristae disappeared. The treatment group compared with the model group, the endoplasmic reticulum and mitochondria swelling was not obvious.(5) The TUNEL results showed that there was a small amount of myocyte apoptosis cells in the normal group. The model group was more than the normal group. The treatment group compared with the model group, there was fewer apoptotic cells.(6) The XBP1U mRNA expression of the model group was more than that in normal group, and it in the treatment group was more than the normal group and model group. The GRP78、 IRE1α、XBP1S、CHOP、PUMA mRNA expression of the model group was more than that in normal group, but it in the treatment group was less than the normal group and model group.(7) Western blotting, according to the results of the treatment group and the model group GRP78, IRE1 α, XBP1, CHOP, PUMA protein expression were higher than normal group, but lower than the model group and the treatment group with statistical significance.Conclusion:(1) In the early stage of diabetes, astragalus membranaceus injection conjunction with puerarin injection can significantly reduce fasting blood glucose, blood lipid, but the effect is not obvious in the late stage.(2) In the early stage of the diabetic cardiomyopathy, there are pathological changes and the myocardial cell apoptosis appear in the myocardial tissue. Astragalus membranaceus injection conjunction with puerarin injection can effectively improve the pathological changes of myocardial tissue and significantly reduce the myocardial cell apoptosis rate.(3) During the process of diabetic myocardial damage, it could inspire ERS in the early stage. Astragalus injection with puerarin injection can inhibit the expression of factors related ERS, is likely to be based on that to inhibit the apoptosis of myocardial cells, to achieve the effect of treatment of diabetic cardiomyopathy. |
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