Effect of Acupuncture at Point Neiguan on Myocardial Ultramicrostructure in Myocardial Hypertrophy Mice / 上海针灸杂志

ABSTRACT

Objective To investigate the effect of acupuncture at point Neiguan on mouse myocardial hypertrophy.Methods Thirty-sixty healthy C57BL6 mice were randomized into blank, model and treatment groups, 12 rats each. In the treatment group, an acupuncture needle was inserted into point Neiguan and retained for 15 min, once daily. After nine days of treatment, the ratios of cardiac weight/tibial length were compared between the groups. Left ventricular myocardial tissues were processed by Masson trichrome staining in every group of mice. The differences in myocardial fiber arrangement and collagen fiber distribution between the groups were observed under the ordinary optical microscope in 100 times of field of vision. Sarcomere structure, myofibril arrangement, collagen fibers and mitochondria in injured myocardial tissues were observed by transmission electron microscopy. Results Heart rate increased significantly in the model group and decreased significantly in the acupuncture group compared with the blank group. Cardiac weight and the ratios of cardiac weight/tibial length increased significantly in the model and acupuncture groups compared with the blank group (P<0.01) and decreased significantly in the acupuncture group compared with the model group (P<0.01). In the model group, myocardial tissues had compensatory hypertrophy with incontinuous status, and myocardial transverse striations had severe disorder/disruption, karyopyknosis appeared and cytoplasmic eosinophilic change became obvious in few of the rats. The results were better in the acupuncture group than in the model group. In the model group, part of myofibrils had focal fusion, interstitial collagen fibers proliferated and mitochondria had swelling and compensatory increase. The results were also better in the acupuncture group than in the model group.Conclusions Acupuncture at point Neiguan can reduce the production of collagen fibers and mitochondria, improve the arrangement of sarcomere structure and delay the progression of myocardial hypertrophy.