The Protective Effect Of Ear Acupuncture On Myocardial Cells Of STZ-induced Diabetic Rats

ObjectiveGreat clinical efficacy can be achieved by ear acupuncture but its working mechanism and the mechanism for intervention of DCM myocardial cells remain to be uncovered. With streptozotocin induced diabetic rats as the research object, this research investigates the mechanism for the diabetes treatment of ear acupuncture with auricular concha area as the acupuncture point. The investigation is achieved by the test of diabetic rats after ear acupuncture treatment on fasting blood-glucose (FBG), glycosylated hemoglobin (GHbAlc), insulin (Ins), change of myocardial cell structure and myocardial cell apoptosis. It is also realized by observing whether damage of diabetes on rat myocardial cells can be relieved by ear acupuncture, whether syndromes can be improved and complications abased. In this way, the research offers the theoretical ground for ear acupuncture application for prevention of diabetes and myocardial cells of diabetes patients.Method1,Fourty Sprague-Dawley male rats which received intraperitoneal injection of streptozotocin were randomly divided into four groups-an auricular acupuncture group (n=10, ear acupuncture in concha area for 30 min once a day). a metformin treatment group(n=10,52mg. kg-1.d-1), an auricular acupuncture and metformin treatment group(n=10, received both ear acupuncture and metformin treatment) and a non-treatment group(n=10)-and compared them with a normal control (n=10). At the beginning of this experiment, FBG, GHbAlc, Ins of all rats were messured.After thirty days of treatment, FPG, GHbAlc, Ins of all rats were detected again. And then cardiac muscle cells' ultrastructure of all the rats were assessed by transmission electron microscope2,HE staining is applied to observe histopathologic structure of rat myocardial cells; Transmission Electron Microscope is applied to observe the ultrastructure of rat myocardial cells; TUNEL method is taken to test in the original place myocardial cell apoptosis and record its situation.Result1,The detection results of FBG,GHbAlc and Ins:At the beginning of this experiment, compared with the normal control, the diabetic rats in the other four groups showed significantly increased FBG, GHbAlc levels (p<0.05, respectively). (2) There were no difference FBG, GHbAlc and Ins levels between the rats before treatment and those after treatment in control group, non-treatment diabetes group (p>0.05, respectively). However, the FDP levels were significantly decreased after treatment in metformin group, auricular acupuncture, auricular acupuncture and metformin group (P<0.05, respectively). FBG of the model group and all other groups are of significant difference (P<0.05). There were no difference GHbAlc and Ins levels between the rats before treatment and those after treatment in metformin group, auricular acupuncture group (p>0.05, respectively). The GHbAlc levels was significantly decreased after treatment in auricular acupuncture and metformin group (P<0.05, respectively), howerver, the Ins was no difference (P>0.05, respectively).2,Histopathologic observation result:(1) Myocardial pathological specimen HE staining:Myocardial cells in the normal group in regular form; Fibers run compact and orderly; Cell apoptosis and necrosis not found; Inflammatory cells infiltrated; Inerstitial fibrosis spotted; Myocardial fibers run relatively disordered with homogenous red stained necrosis evident with few of inflammatory cells infiltrated; Glycogen sediment evident in partial myocardial fibers; Myocardial fibers in the melbine group run compact and orderly only with edema and apoptosis of partial myocardial cells; Myocardial fibers in the acupuncture group in a relatively loose form with mild disorder or contraction change with homogenous red stained necrosis and few filtrated inflammatory cells; Myocardial fibers of the metformin and auricular acupuncture group in relatively loose form; They run in relative disorder with occasional edema and apoptosis of myocardial cells; Situation in the two groups is similar to that of normal group. (2) Myocardial ultrastructure:In the normal group, myofilament structure and sarcomere structure are clear; Nucleus is in the center of the myocardial cell and euchromatin is the major part inside the nucleus. Partial sarcomere dislocated in the model group; Muscle fibers are loose, broken, separated and partially dissolved; Mitochondria swollen; Crests decreased and sparse; Glycogenosome increased; Sarcoplasmic reticulum expanded; Intercalated disc expanded, broken, and unclear; Microvascular endothelial cell nucleus is deformed; Heterochromatin increased and gathered beside; Capillary lumen is narrow and small. In the metformin group, the para position of sarcomere is basically in order and no obvious dissolving of muscle fibril; Arrangement of muscle fiber sparse; only few dissolving of crests inside the mitochondria; Sarcoplasmic reticulum mildly expanded;Intercalated disc is irregular and broke off. The myofilament structure in the auricular acupuncture group is quite clear and Z-line becomes blurred and thin; Muscle fiber sparse; Mitochondria mildly swollen; few crests dissolved; some few vacuolar degeneration inside; Glycogenosome increased; Intercalated disc complete. In metformin and auricular acupuncture group, the arrangement of muscle fiber is orderly; Z-line obvious; Mitochondria slightly swollen; Intercalated disc and myolemma complete. (3) Apoptosis of rat myocardial cells: The nucleus in the positive cell turns out as brown or bronzed; Chromatins in the nucleus condensed into dense particles and nuclei in different sizes. A few of degenerated cells can be spotted in the normal group and many degenerated myocardial cells in the model group; Diffused distribution of degenerated cells across all groups; Apoptosis indexes of the normal group and the model group are of significant difference (P<0.01); Apoptosis indexes of the model group and all other groups are of significant difference (P<0.05).ConclusionIt is suggested that decrease of FBG and GHbAlc, alleviation of high blood sugar damage on the myocardial cells and less apoptosis of myocardial cells can all be realized by ear acupuncture, which serves to protect the structure of myocardial cells and postpone myocardial degeneration.