疼痛模型大鼠下丘脑和脊髓P物质的含量变化

目的疼痛模型大鼠下丘脑和脊髓P物质（substance P，SP）的含量变化。方法左足跖皮下注射5％甲醛50μl建立大鼠疼痛模型，将动物随机分成空白对照组，生理盐水对照组和疼痛模型组，采用放射免疫分析法测定股动脉血、下丘脑和脊髓中SP的含量。结果疼痛模型组雄性S-D大鼠血浆中及下丘脑和脊髓SP含量分别与空白对照组、生理盐水对照组差别有统计学意义（P〈0．05）；而空白对照组与生理盐水对照组差别无统计学意义（P〉0．05）。结论皮下注射5％甲醛可致疼痛症状产生；提示皮下注射甲醛所致疼痛可通过下丘脑和脊髓组织中的SP释放增加，所致无菌性炎症反应而引起疼痛症状。

The Content Variation of Substance P in Hypothalamus and Spinal Cord of Pain Models of Rat

Objective To investigate the content variation of Substance P （SP） in hypothalamus and spinal cord of pain models of rat with radioimmunoassay （RIA）. Methods Rats were divided randomly into blank control group, saline group（injected subcutaneously 0.9%NaCI into left voix pedis） and pain model group（injected subcutaneously 5%formaldehyde into left voix pedis）. The immunoractive SP in femoral artery, hypothalamus and spinal cord was detected by RIA. Results The content of SP in femoral artery, hypothalamus and spinal cord was different significantly in pain group than that in other control groups （P〉0. 05）, but no difference between two control groups（P〉0. 05）. Conclusion The up-regulation of SP in femoral artery, hypothalamus and spinal cord implied that the subcutaneous injection of formaldehyde may induce the sterile inflammatory response and result in the symptom of pain.