CAJ | 학술논문

目的研究内脏高敏感大鼠结肠细胞因子和5-羟色胺(5-HT)转运体(SERT)的表达,为细胞因子和5-HT系统在内脏高敏感性产生机制中的作用提供依据.方法 16只胎龄小于8 d的新生SD大鼠被随机分为2组,每组8只.采用乳鼠醋酸灌肠法建立大鼠慢性内脏高敏感动物模型,以盐水灌肠作为对照组.待乳鼠成年后应用直肠内球囊扩张检测腹碓收缩阈值和弓背抬起阈值的方法评估其内脏敏感性;通过检测髓过氧化物酶(MPO)评价肠道黏膜炎症程度;采用免疫组化的方法检测大鼠结肠组织中IL-1β和TNFα的水平;采用Western blot方法检测大鼠结肠组织SERT的表达水平.结果两组大鼠体重增长趋势基本一致,HE染色显示结肠黏膜未见明显急、慢性炎症改变;两组大鼠结肠组织MPO水平相比,差异无统计学意义[(0.497±0.570)U/g湿片比(0.623±0.739)U/g湿片,P=0.724];实验组大鼠腹壁收缩阈值和弓背抬起阈值分别为(0.19±0.06)ml和(0.47±0.13)ml,较对照组大鼠[(0.40±0.14)ml和(0.91±0.26)ml]显著减低,P＜0.01;实验组大鼠结肠IL-1β、TNFα的表达水平(0.196±0.002和0.194±0.001)均显著高于对照组(0.185±0.001和0.182±0.001),P＜0.01;实验组大鼠SERT蛋白相对表达水平(0.298±0.038)较对照组(0.634±0.200)显著减低,P＜0.05.结论内脏高敏感大鼠IL-1β和TNFα的表达升高,SERT的表达水平减低,细胞因子与SERT可相互影响,IL-1β、TNFα和SERT可能在大鼠内脏高敏感性的发生机制中具有一定的作用.
목적 연구내장고민감대서결장세포인자화5-간색알(5-HT)전운체(SERT)적표체,위세포인자화5-HT계통재내장고민감성산생궤제중적작용제공의거.방법 16지태령소우8 d적신생SD대서피수궤분위2조,매조8지.채용유서작산관장법건립대서만성내장고민감동물모형,이염수관장작위대조조.대유서성년후응용직장내구낭확장검측복대수축역치화궁배태기역치적방법평고기내장민감성;통과검측수과양화물매(MPO)평개장도점막염증정도;채용면역조화적방법검측대서결장조직중IL-1β화TNFα적수평;채용Western blot방법검측대서결장조직SERT적표체수평.결과 량조대서체중증장추세기본일치,HE염색현시결장점막미견명현급、만성염증개변;량조대서결장조직MPO수평상비,차이무통계학의의[(0.497±0.570)U/g습편비(0.623±0.739)U/g습편,P=0.724];실험조대서복벽수축역치화궁배태기역치분별위(0.19±0.06)ml화(0.47±0.13)ml,교대조조대서[(0.40±0.14)ml화(0.91±0.26)ml]현저감저,P＜0.01;실험조대서결장IL-1β、TNFα적표체수평(0.196±0.002화0.194±0.001)균현저고우대조조(0.185±0.001화0.182±0.001),P＜0.01;실험조대서SERT단백상대표체수평(0.298±0.038)교대조조(0.634±0.200)현저감저,P＜0.05.결론 내장고민감대서IL-1β화TNFα적표체승고,SERT적표체수평감저,세포인자여SERT가상호영향,IL-1β、TNFα화SERT가능재대서내장고민감성적발생궤제중구유일정적작용.
Objective To assess the expression of TNFα, IL-1β and the serotonin transporter (SERT) in adult rats of chronic visceral hypersensitivity induced by colon irritation during postnatal development, and to provide evidence to clarify the complex relationship between inflammatory cytokines and SERT among visceral hypersensitivity. Methods Sixteen neonatal male Sprague-Dawley rats were randomly separated into two groups undergoing different treatments. The irritated group ( n = 8 ) was received intracolonic injections of acetic acid(0.5%) between postnatal days 8 and 21 and another group ( n = 8 )was received colonic infusion with 0. 9% saline served as control. When they became adults( ages 7 weeks),the threshold intensity for a visually identifiable contraction of the abdominal wall and body arching were recorded during rectal distention (RD) to evaluate visceral hypersensitivity. Histological evaluation and MPO activity assay were performed to quantify the inflammation. The expression of cytokine of colon was assessed through immunohistochemistry. The expression of SERT was examined by Western blot. Results Histological examination of the tissues showed no significant structural damage or loss of crypts. The MPO levels in both groups were similar[(0. 497 ±0. 570) unit/g vs (0. 623 ±0. 739) unit/g, P =0.724]. The threshold to elicit a distinctive abdominal muscle contraction in response to RD decreased from (0.40 ±0. 14) ml in the control group to (0. 19 ±0.06)ml in the irritated group. And the threshold for bodying arching decreased from (0.91 ± 0. 26 ) ml in the control group to ( 0. 47 ± 0. 13 ) ml in the irritated group (P ＜ 0. 01 ). Cytokine immunoreactivity was increased in the irritated group when compared to the control group (TNFα: 0. 194 ±0. 001 vs 0. 182 ±0. 001, P ＜0. 01; IL-1β: 0. 196 ±0. 002 vs 0. 185 ±0.001, P＜0. 01 ), while SERT expression were reduced in the irritated group (0. 298 ±0. 038 vs 0. 634 ±0. 200, P＜0. 05). Conclusion There is an increase in the proinflammatory cytokines and a decrease in the SERT expression associated with the presence of chronic visceral hypersensitivity, both of them may play an important role in the pathogenesis of visceral hypersensitivity.