The decrease of Kv1mRNA expression in dorsal root ganglion in rats

Objective:To observe the expressive variety of Kv1mRNA in dorsal root ganglion on neuropathic pain by chronic con-striction injury(CCI).Methods:Sixty male Sprague-Dawley rats were randomly divided into two groups:CCI group and control group,Recording the responsiveness to mechanical and thermal stimuli before and after sciatic nerve constriction injury.For hemi-quantitative analysis,RT-PCR method was used in the detection of the levels of Kv1mRNA in dorsal root ganglion at the 3th,7th,14th,28th day fol-lowing sciatic nerve constriction injury.Results:The rats' responsiveness to mechanical and thermal stimuli and pain behavior were signifi-cantly increased on postoperative days after sciatic nerve ligation compared with preoperative condition(P0.05).Electrophoresis of the RT-PCR products showed that the relative expression levels of the Kv1.2,1.4,1.6mRNA were obviously declined at 3 days and Kv1.1mRNA was obviously declined at 7 days following CCI(P0.01).No significant changes in Kv1.5mRNA levels were detectable at any day.Conclusion:The CCI rats' sensitivity to thermal and mechanical stimuli was significantly increased following sciatic nerve con-striction injury.This could be related to the downregulation of Kv1mRNA expression in dorsal root ganglion.