Modification of autonomic balance by electrical acupuncture does not affect baroreflex dynamic characteristics

We have demonstrated that modification of autonomic balance by electrical vagal stimulation delays progression of cardiac dysfunction and cardiac remodeling, and prolongs survival in rats with severe heart failure. We have also shown that we were able to modify autonomic balance by electrical acupuncture at the acupoint of Zusanli, potentially applicable for the treatment of heart failure. We examined the effect of the acupuncture on the dynamic characteristics of the baroreflex system to exclude the possible deleterious effect on orthostatic tolerance.

In anesthetized 8 and 6 rabbits, we examined static and dynamic characteristics of baroreflex, respectively, with and without electrical acupuncture (1 Hz, 5 mA, and 5msec). Dynamic characteristics were examined by imposing pseudorandom binary changes in isolated carotid sinus pressure.

With the stimulation condition to decrease arterial blood pressure and sympathetic nerve activity (resulted form decreased response range of neural arc), either of the dynamic characteristics of neural arc or those of peripheral arc did not change by electrical acupuncture at Zusanli.

We conclude that application of electrical acupuncture at Zusanli can suppress sympathetic nerve activity but does not affect the dynamic characteristics of the arterial baroreflex system, indicating no deleterious effect on orthostatic tolerance.