慢性胰腺炎疼痛模型大鼠背根神经节胰腺节段的确定

Determination of dorsal root ganglion segments projecting to the pancreas in a rat model of chronic pancreatitis pain

目的:建立慢性胰腺炎(chronic pancreatitis,C P)模型,检测模型大鼠背根神经节(dorsal root ganglion,DRG)的胰腺节段,并通过物理及化学检测方法论证模型可行性,为进一步探讨慢性内脏疼痛的发生机制奠定基础.方法:选取成年SD大鼠为实验对象,分为实验组和对照组,实验组一次性经尾静脉注射二丁基二氯化锡溶液,对照组注射等剂量的乙醇溶液,注药前后不同时间点测定机械缩足反射阈值,8 wk后处死两组大鼠,通过HE染色对比两组大鼠胰腺组织病理变化,选取正常大鼠行1,1'-双十八烷基-3,3,3',3'-4甲基吲哚羰花青-高氯酸盐(1,1'-dioctadecyl-3,3,3',3'-tetramethindo-carbocyanine perchlorate,Dil)逆行示踪明确支配胰腺的DRG段,通过RT-PCR法测两组大鼠DRG的c-fos指标的m RNA的表达变化.结果:注药8 wk后,与对照组相比,实验组大鼠胰腺组织显示明显的慢性炎症表现;痛阈值明显降低;Dil逆行示踪证实支配胰腺组织的脊髓神经表达节段在T8-12,DRG的c-fos表达较对照组增多(P<0.05).结论:CP疼痛模型成功,支配胰腺的DRG段在T8-12,c-fos的表达在慢性疼痛刺激条件下明显增多,提示模型成功.

AIM：To establish a rat model of chronic pancreatitis and determine dorsal root ganglion（DRG） segments projecting to the pancreas,in order to lay a foundation for further study of the pathogenesis of chronic visceral pain METHODS：Adult male Sprague Dawley ratswere randomly divided into an experimental group and a control group.The experimental group was intravenously given 8 mg/kg body weight dibutyltin dichloride to induce chronic pancreatitis,and the control group was injected with ethanol solution.Mechanical withdraw threshold at different time points was detected.Rats of the two groups were sacrificed after 8 wk.HE staining was used to detect the histological changes of pancreatic tissue,and RT-PCR was used to measure c-fos mR NA expression in DRG.RESULTS：Compared with the control group,the rats in the experimental group showed chronic inflammation in pancreatic tissue at 8 wk and had significantly decreased mechanical withdraw threshold.1,1＇-dioctadecyl-3,3,3＇,3＇-tetramethindo-carbocyanine perchlorate（Dil） retrograde tracing confirmed that the dorsal root ganglion（DRG） segments projecting to the pancreas were T8-12,and c-fos expression in DRG significantly increased（P〈0.05）.CONCLUSION：The dorsal root ganglion（DRG） segments projecting to the pancreas are T8-12.c-fos expression in chronic DRG significantly increases in rats with chronic pancreatitis pain.