Objective: To select better stimulating methods for exploring mechanisms of formation of the higher thermal trace.

Methods: Healthy rabbits were used in this study. Hair at the four limbs and back was removed to expose the skin. Acupoints selected were "Neiguan" (PC 6), "Waiguan" (SJ 5), "Housanli", "Fuliu" (KI 7), "Mingmen" (DU 4), "Yaoyangguan" (DU 3) and "Shenshu" (BL 23). Stimulation methods used were hand needling (after insertion, the needles were lifted, thrusted and twirled for a while and then retained for l5min), electroacupuncture (EA, 1Hz of frequency, a suitable strength to evoke local muscular trembling when stimulating the acupoint, duration of needle retaining being 15min), moxibustion (warm moxibustion over the acupoint for l5min and relay moxibustion), red-hot needling (fast pricking without retaining of the needle) and subcutaneous catgut embedding (l0-gauge catgut was implanted in the subcutaneous tissues for 24hr, 48hr, 72hr and 96hr). Changes of thermal trace on the skin were observed and recorded by using infrared thermography.

Results: (1 ) The occurrence rate of higher thermal trace in moxibustion group (n=54) was highest, being about 50.0% on the average; and those of EA group (n=l8), catgut embedding group (n=18), red-hot needling group (n=4) and hand needling group (n=54) were 38.9%, 27.8%, 25.0% and l8.5% respectively, (2) The length of thermal trace of the moxibustion group was longest, 6 - l0cm on the average. That of EA group was second, about 5 -8cm; and those of red-hot needling, hand needling and catgut embedding group were from 3 to 7cm on the average; and (3) The elevated temperature values along the channel in moxibustion group and EA group were 0.7 - 1.0°C - 0.8°C and 0.5 - 0.8°C separately at the average; and those of the rest groups were from 0.3°C to 0.7°C at the average.

Conclusion: The warm moxibustion and EA stimulating methods at the acupoint are better in evoking higher thermal trace along channels.

By Zhang Dong, Fu Weixing, Wang Shuyou,