腹外斜肌放电测量在幼鼠内脏痛觉高敏感模型评价中的应用

Assessment of the young rat model of visceral hypersensitivity by measuring electrical discharge of external oblique

目的探索幼鼠腹外斜肌放电测量的适宜条件,为是否成功建立内脏痛觉高敏感幼鼠模型提供一种较为客观、有效的评价方法。方法8日龄Sprague-Dawley大鼠随机分成实验组和对照组。实验组每日给予1次直结肠刺激(CI),连续7d;对照组不给予CI。随后,在6周龄时用腹外斜肌放电方法测量结直肠在不同的扩张压力下的腹外斜肌放电幅度,以评估幼鼠的内脏痛觉敏感性。结果当结直肠扩张(CRD)为30,45mmHg时,实验组腹外斜肌放电波幅边缘估计均值显著高于对照组(P<0.01);在控制组别等影响因素后,当CRD为60,75mmHg时,雌鼠腹外斜肌放电幅值的边缘估计均值均高于雄鼠(P<0.05)。结论腹外斜肌放电证实在新生期进行持续的CI能造成幼鼠痛阈下降,出现慢性内脏高敏感性,并且有性别差异。电生理评价方法达到定量检测,受较少人为主观因素的影响,能较客观反应动物内脏痛觉的致敏效应,特别适用于幼年动物模型。

Objective To study the Value of measuring electrical discharge of external oblique in assessment of young rat model of visceral hypersensitivity. Methods Eight-day-old neonatal Sprague-Dawley rats were randomly assigned to two groups： an experimental group and a control group （n = 16 each）. Rats in the experimental group were subjected to mechanical colorectal irritation daily for 7 consecutive days, while the rats in the control group did not received colorectal irritation treatment. On the 6th week of their lives, the spike amplitude of external oblique were measured to evaluate the bowel sensitivity. Results When the colorectal distention （CRD） pressure was 30 and 45 mmHg, the 95% confidence interval of the spike amplitude in the experimental group was significantly higher than that in the control group （ P 〈 0.01 ）. When the CRD pressure were 60 and 75 mmHg, the 95% confidence interval of the spike amplitude in female rats was significantly higher than that in males （ P 〈 0.05 ）. Conclusions The electrical discharge of external oblique confirmed that chronic colorectal irritation in neonatal rats can result in a chronic visceral hypersensitivity in the juvenile stage, with gender differences. Electrophysiological assessment is a quantitative test, and can objectively reflect visceral sensibility of pain.