["Houxi (SI 3) communicating the governor vessel" verified with the infrared thermal imaging technology]

To compare the effect on facial acupoint temperature between acupuncture at Houxi (SI 3) and Dazhui (GV 14) so as to verify "Houxi (SI 3) communicating the governor vessel" based on the infrared thermal imaging technology.

Thirty-five healthy subjects (5 cases dropped off) were collected and before-after study in the same subject was adopted. The subjects were successively assigned into a sham-acupuncture group, a Houxi group, a Wangu group and a Dazhui group. Sham-acupuncture at Houxi (SI 3) on the left, acupuncture at Houxi (SI 3) on the left, Wangu (SI 4) on the left and Dazhui (GV 14) were given respectively. One intervention was given and the needles were retained for 30 min in each group. 30 min before and after acupuncture, the infrared thermal images of the face were collected, and the facial temperature was compared among the following 5 acupoints, i.e. Yintang (GV 24⁺), Suliao (GV 25), Shuigou (GV 26), Duiduan (GV 27) and Chengjiang (CV 24).

After acupuncture, the facial temperature at Yintang (GV 24⁺) and Chengjiang (CV 24) was increased compared before acupuncture in the sham-acupuncture group (P<0.01, P<0.05). The facial temperature at Suliao (GV 25) in the Houxi group was reduced after acupuncture (P<0.05). In the Wangu group, the temperature at Yintang (GV 24⁺) was increased compared before acupuncture (P<0.01). The facial temperature was increased at Duiduan (GV 27) and Chengjiang (CV 24) compared before acupuncture in the Dazhui group (P<0.01, P<0.05). The differences of facial temperature at Chengjiang (CV 24) and Suliao (GV 25) after acupuncture were larger than before acupuncture in the Houxi group and the Dazhui group (P<0.01). In comparison with the temperature at Suliao (GV 25) of the same group, the differences of facial temperature before and after acupuncture at Yintang (GV 24⁺), Shuigou (GV 26), Duiduan (GV 27) and Chengjiang (CV 24) were increased in the Houxi group (P<0.01, P<0.05); while, the increase was also obtained at Yintang (GV 24⁺), Shuigou (GV 26), Duiduan (GV 27) and Chengjiang (CV 24) in the Dazhui group (P<0.05, P<0.01). The difference of facial temperature at Yintang (GV 24⁺) before and after acupuncture was increased compared with Suliao (GV 25) in the Wangu group (P<0.05).

Acupuncture at Houxi (SI 3) generates a similar thermal effect as Dazhui (GV 14). It regulates and dissipates the core temperature to "govern the yang qi of the whole body".