CAJ | 학술논문

目的：探讨谷氨酰胺对非酒精性脂肪性肝病（NAFLD）大鼠肠黏膜上皮细胞紧密连接蛋白的调控，及其对大鼠肠黏膜屏障的保护作用。方法建立NAFLD大鼠模型。实验分为正常组、模型组和谷氨酰胺组各12只，以第8周和第12周为时间点，观察肝脏病理学改变、记录肝指数，鲎试剂终点比色法检测内毒素水平，ELISA 法测定TNF-α，western blot法检测肠道occludin蛋白量，免疫组化染色明确蛋白定位及分布。结果病理证实高脂饮食诱导NAFLD鼠模成功。在第8周模型组和谷氨酰胺组肝指数、内毒素及TNF-α含量均高于正常组（3．14±0．76，3．07±0．65比2．84±0．55；0．213±0．019，0．194±0．010比0．120±0．014；25．76±3．54，23．65±2．78比7．84±1．55）；模型组和谷氨酰胺组差异无统计学意义（P＞0．05）。第12周时，与正常组比较，模型组和谷氨酰胺组上述指标升高明显（3．75±0．56，3．47±0．73比2．75±0．91；0．279±0．033，0．203±0．012比0．114±0．021；29．73±5．34，28．77±3．61比6．84±1．87，均P＜0．05）；谷氨酰胺治疗后血清内毒素水平的下降与模型组相比，差异有统计学意义（P＜0．05）。NAFLD 大鼠存在肠道occludin 蛋白量减少，谷氨酰胺具有上调其表达的作用。3组中occludin蛋白定位无明显区别，但其棕褐色染色强度及范围在正常组及谷氨酰胺组更强。结论谷氨酰胺能修复NAFLD大鼠肠黏膜屏障，其机制与降低TNF-α含量、上调肠上皮细胞紧密连接蛋白occludin的表达，进而改善内毒素血症等有关。
목적：탐토곡안선알대비주정성지방성간병（NAFLD）대서장점막상피세포긴밀련접단백적조공，급기대대서장점막병장적보호작용。방법건립NAFLD대서모형。실험분위정상조、모형조화곡안선알조각12지，이제8주화제12주위시간점，관찰간장병이학개변、기록간지수，후시제종점비색법검측내독소수평，ELISA 법측정TNF-α，western blot법검측장도occludin단백량，면역조화염색명학단백정위급분포。결과병리증실고지음식유도NAFLD서모성공。재제8주모형조화곡안선알조간지수、내독소급TNF-α함량균고우정상조（3．14±0．76，3．07±0．65비2．84±0．55；0．213±0．019，0．194±0．010비0．120±0．014；25．76±3．54，23．65±2．78비7．84±1．55）；모형조화곡안선알조차이무통계학의의（P＞0．05）。제12주시，여정상조비교，모형조화곡안선알조상술지표승고명현（3．75±0．56，3．47±0．73비2．75±0．91；0．279±0．033，0．203±0．012비0．114±0．021；29．73±5．34，28．77±3．61비6．84±1．87，균P＜0．05）；곡안선알치료후혈청내독소수평적하강여모형조상비，차이유통계학의의（P＜0．05）。NAFLD 대서존재장도occludin 단백량감소，곡안선알구유상조기표체적작용。3조중occludin단백정위무명현구별，단기종갈색염색강도급범위재정상조급곡안선알조경강。결론곡안선알능수복NAFLD대서장점막병장，기궤제여강저TNF-α함량、상조장상피세포긴밀련접단백occludin적표체，진이개선내독소혈증등유관。
Objective To investigate the effects of glutamine on the expression of intestinal epithelial tight junction protein in NAFLD rat and to confirm its protective effect on the intestinal mucosal barrier. Methods NAFLD rat model was established. 36 SD rats were divided into normal group,model group and glutamine group. Liver index,hepatic pathology, serum endotoxin and TNF-αwere recorded at the 8th and 12th week. Intestinal occludin protein expression was detected by western blot. Its orientation and distribution was detected by immunohistochemistry. Results NAFLD rat model was established successfully by high fatty diet. At 8th week liver index,endotoxin and TNF- αcontent of model group and glutamine group were higher than those in normal group,and no significant differences were observed (3.14±0.76,3.07± 0.65 vs 2.84±0.55;0.213±0.019,0.194±0.010 vs 0.120±0.014;25.76±3.54,23.65±2.78 vs 7.84±1.55);so did glutamine group when compared with model group. At 12th week,indexes as above increased significantly in model group and glutamine group,compared with normal group (3.75±0.56,3.47±0.73 vs 2.75±0.91;0.279±0.033,0.203± 0.012 vs 0.114±0.021;29.73±5.34,28.77±3.61 vs 6.84±1.87,P<0.05). Serum endotoxin was decreased significantly after glutamine treatment (0.203±0.012 vs 0.279±0.033,glutamine group vs model group,P<0.05). Intestinal occludin protein expression was weaker in NAFLD rats than that in the other two groups. However,glutamine can upregulate its expression. No significant differences of occludin localization among three groups were found,but the intensity and range of brown staining was stronger in normal and glutamine group. Conclusion Glutamine could repair intestinal mucosa barrier in rats with NAFLD. Its mechanism involves reducing serum TNF-α,up-expressing intestinal epithelial tight junction protein named occludin,and then ameliorating endotoxemia.