The Interaction of Mast Cells and Cardiac Sympathetic Nerves During Acupuncture in Acute Myocardial Ischemia Rats

Background: Acupuncture has been shown to regulate visceral functions. However, the specific mechanism remains unknown. Objective: This study attempted to investigate cardiac sympathetic nerve activity response to acupuncture and its activation effect on mast cells in the acupoint area. Materials and Methods: A rat model of acute myocardial ischemia (AMI) was prepared by ligating the left anterior descending artery branch. After dissecting a branch of the cardiac sympathetic nerves, the left Neiguan point (PC 6) was stimulated with acupuncture. Then, the skin tissues of acupoint area were sampled and stained with neutral red after killing the rats. Main Outcome Measures: Nerve discharges and electrocardiograph readings were recorded during acupuncture. Heart rate variability (HRV) and the power spectrum of nerve discharges were used as markers for analysis. Ratios of degranulated to total mast cells were also calculated. Results: AMI caused an increase in the ratio of low frequency/high frequency (LF/HF) of HRV, and the spectral power of cardiac sympathetic nerve activity increased (p<0.01), whereas after acupuncture, cardiac sympathetic nerve activity decreased (p<0.05), LF/HF ratio decreased (p<0.01), and degranulation rate of mast cells increased (p<0.01). In contrast, after disodium cromoglycate pretreatment, the degranulation rate decreased and the acupuncture effect weakened. Conclusions: AMI may increase sympathetic activity, whereas acupuncure can not only induce degranulation of mast cells but also can regulate cardiac sympathetic nerve activity to reduce tension of sympathetic nerves, protecting the heart from AMI.