Contributions of K ATP within the paraventricular nucleus in the modulation of inflammatory pain in rats / 中国药理学通报

ABSTRACT

Aim To explore the role of KATP in the pa-raventricular nucleus in inflammatory pain. MethodsMale Sprague-Dawley rats,250~280 g, were randomly assigned into 5 groups ( each, n =6 ) Normal group, Saline group ( for control, subcutaneous injection of 100 μl of saline into the plantar surface of the left hindpaw) , CFA group ( subcutaneous injection of 100μl of complete freund's adjuvant into the plantar sur-face of the left hindpaw) , Vehicle group ( treated with dimethylsulfoxide), KATP selective agonist group(trea-ted with diaoxide) . Rats in each group were tested for TWL with radiant heat apparatus. Immunofluorescent technique was used to label KATP in PVN and c-Fos in lumber spinal cord. Three days after injected with CFA, a selective KATP agonist, diaoxide, was injected into one side of PVN to test its effect on inflammatory pain and c-Fos expression in lumber spinal cord. Re-sults ① Compared with pre-operation and saline group, rats showed significantly lower TWL on day 1, 3, 7 after injection of CFA;the numbers of KATP posi-tive cells were significantly lower; the numbers of c-Fos positive cells were significantly higher. ② Com-pared with those of vehicle group, TWL and the num-ber of c-Fos in lumber spinal cord were both signifi-cantly lower after injection of diaoxide into one side of PVN. Conclusion KATP in PVN is related to inflam-matory pain.