Abstract
It is generally accepted that manual acupuncture reduces heart rate via autonomic nerves in humans and in anesthetized animals. However, it is also known that sometimes it is ineffective in humans. To test the hypothesis that the mental state of the subject influence the acupuncture-induced autonomic response of the heart rate, we examined the effects of acupuncture on heart rate at normal condition and stressful condition in healthy adult subjects. We performed mental arithmetic load to induce a stressful condition. A 40-mm-long needle with a diameter of 0.18 mm was inserted to a depth of about 15 mm at the Tsusanli acupoint (ST-36) of the right leg. Sparrow-pecking stimulation was performed at a stimulation frequency of 1 Hz for 4 minutes. The heart rate was calculated using R-R intervals obtained from an electrocardiogram. Acupuncture significantly decreased the heart rate in normal condition. The maximum mean decrease for all subjects was 6.1 + 3.0 beats/min. A mental arithmetic load increased heart rate. The maximum mean increase for all subjects was 4.3 + 2.5 beats/min. In a stressful condition, the acupuncture-induced decrease in heart rate was significantly attenuated. Therefore, we conclude that the reaction caused by acupuncture stimulation is affected by the mental state of the subject. [J Physiol Sci. 2008;58 Suppl:S159]
