Abstract:The regulatory effects of electro-acupuncture on thermal hyperalgesia in a peripheral mononeuropathy model were observed in rats. Peripheral mononeuropathy was induced in adult rats by crushing an unilateral common sciatic nerve with 50g in force lasting for 5 min at 4 points along the nerve. The postoperative plantar cutaneous hyperalgesic response to noxious radiant heat stimulation was measured by a newly developed thermal pain threshold detector in awake and unrestrained condition. The rats with crushed sciatic nerve were divided randomly into four groups: control, electro-acupuncture 1 (EA1). EA2 and EA3. In the 3 EA groups,the electrical pulses generated by a WQ-6F electronic apparatus with frequency of 50 Hz and intensity ranging from 1-1. 5 mA were delivered to Yanglingquan (GB34)and Xuanzhong (GB39) points. The rats in control were not stimulated by electro-uacupuncture,while those in EA1,EA2 and EA 3 groups were given electro acupunctre every 1, 2 and 3 days respectively. It was noticed that the unilateral injury of the sciatic nerve could induce thermal hyperalgesia in the affected hind paw. lasting for about half a month. The hyperalgesia could be relieved by electro- acupunctre given once every day or every other day but not every 3 days. The results indicate that in the treatment of hyperalgesia,the interval for applying acupuncture is an important factor determining its analgesic effects.
