TRANSIENT INCREASE IN HUMAN MUSCLE SYMPATHETIC-NERVE ACTIVITY DURING MANUAL ACUPUNCTURE

To clarify the effects of manual acupuncture on the autonomic nervous system, we measured efferent muscle sympathetic nerve activity (MSNA) from the right peroneal nerve while simultaneously recording blood pre ssure and heart rate both during the resting period and after manual a cupuncture applied to the Tsusanli acupoint of the same limb. The need le was rotated intermittently for 30 s at 5-min intervals. MSNA increa sed transiently with the suppression of heart rate during rotation of the acupuncture needle. No consistent change in blood pressure was fou nd throughout the acupuncture session. After removal of the needle, bo th the MSNA and heart rate returned to the initial control values, and the mean blood pressure showed an increase over the resting value. MS NA showed a negative correlation with heart rate in four out of five s ubjects who received acupuncture. These results suggest that the coact ivation of cardiac vagal and muscle sympathetic nerves is evoked by th e acupuncture maneuver.