Experimental Study On The Effect Of Acupuncture At Neiguan Point On Cardiac Function In Hypertrophic Mice

Objectives:The changes of heart rate and myocardial tissue induced by isoproterenol in mice with hypertrophic cardiomyopathy were observed by acupuncture at neiguan point,which provided theoretical basis for acupuncture treatment of hypertrophic cardiomyopathy.Methods:50 male C57BL6 mice,weighing 20-25 g and free of any disease,were selected and injected with the model drug isoproterenol.The animal model of cardiac hypertrophy was established by continuous subcutaneous injection of the back for 14 days.Before the experimental modeling,normal heart rate and weight of each mouse were recorded,and each mouse was marked with different ear markers to distinguish them.The mice were randomly divided into 5 groups,namely: normal group,model group,bilateral neiguan acupuncture group,tail non-acupuncture group,and drug treatment control group.Ten were selected from each group for the experiment.In addition to the normal group,mice in the other five groups were injected with the model drug.On this basis,both sides of "neiguan point" were pricked once a day in the acupuncture group,and the needles were retained for 15 minutes each time.Mice in the normal group were injected with normal saline(1ml/kg)every day after anesthesia for 14 days.In the model group,the model drug isoproterenol(15mg/kg)was injected subcutaneously in three parts every day for 14 days.In the tail non-point acupuncture group,the tail root of mice was pricked once a day for 15 minutes each time,for a total of 14 days.Mice in the drug treatment group were given atenolol(10mg/kg)once a day for 14 days.The reference standard for mouse acupoint selection in the experiment: neiguan acupoint was selected according to the "map of acupoint of acupuncture and moxibustion in experimental animals" developed by experimental acupuncture and moxibustion research institute of Chinese acupuncture and moxibustion society.Neigenguan was positioned on the metacarpal midline of the forearm and 1mm on the transverse wrist.Experimental results:1.Heart rate: the heart rate of normal mice was(354.22±49.86)beats /min,and theaverage heart rate of the model group was 566 beats /min.The heart rate of the drug group and the neiguan acupuncture group significantly decreased,with the average heart rate of352 beats /min and 365 beats /min,respectively.The heart rate of the tail acupuncture group did not decrease,but slightly increased,which did not play a role in lowering the heart rate.Compared with the model group,there was basically no effect.2.Under electron microscope,the structure of the normal group was basically clear,with regular arrangement of myofibrils,and rows of mostly oval mitochondria with intact internal and external membranes and clear ridges.In contrast,the inner and outer membranes of mitochondria in the model group were not clear and the ridge structure was not clear.There is a compensatory increase in the number of mitochondria and swelling,resulting in the proliferation of interstitial collagen fibers.No sarcomere injury was found in the drug treatment group.There was a small amount of collagen fiber proliferation in the interstitium of the neiguan group after acupuncture,the vascular endothelial mitochondria were slightly swollen,the endothelial cells were continuous,the sarcomere structure was acceptable,and the myofibrils were not damaged.The number of mitochondria,lysosomes and collagen fibers in the non-acupoint group increased at the same time.3.Analysis of myocardial fibrosis with MASSON staining at 100 x and 400 x magnification under light microscope: under the microscope,the collagen fibers filled with tissue interstroma were stained blue,and the normal group of mice showed well-arranged myocardial fibers with complete morphology,plump cell serous fluid,plump nuclei,normal myocardium,and no obvious abnormalities.In contrast,the myocardial tissue in the model group presented compensatory hypertrophy and discontinuity,and a few myocardial transverse veins were fractured or disordered.The interstitium was covered with blue collagen fibers,and the nuclear condensation was obvious.Compared with the model group,the disordered cell state was significantly reduced in the drug treatment group and the acupuncture neiguan group.4.groups of mice were magnified 100 times and 400 times respectively under HE dyed myocardial fibrosis analysis: normal group visible muscle fibers,complete and neat rows,the nucleus is located in the middle of the muscle fibers,cardiac muscle and myocardial interstitial not seen obvious anomaly,cut the myocardial cells,visible longitudinal sectionhorizontal grain clarity,nuclei in the middle and transverse section for irregular polygon,visible myofibril radial arranged around the nucleus.The model group had obvious myocardial transverse striation disorder and fracture.Mild to moderate hyperemic edema,fibrous swelling,unclear nuclei.Compared with the model group,the needling group and the drug group showed that the degree of absence of oocytes and rupture of myocardial cells was reduced.There was no significant difference between the tail acupuncture group and the model group.Experimental conclusions:1.Acupuncture at neiguan point group and drug therapy group were both effective in the treatment of isoprenaline induced cardiac hypertrophy in mice.2.Acupuncture at neiguan point group and drug treatment group could reduce the heart rate of mice with isoprenaline induced cardiac hypertrophy,but there was no significant difference between the two groups.3.Acupuncture at neiguan could improve the ultrastructure of myocardial cells induced by isoproterenol in mice with myocardial hypertrophy,which was superior to the drug treatment group.