非酒精性脂肪性肝病对肠道炎症及通透性的影响

目的通过高脂饮食建立非酒精性脂肪性肝病(NAFLD)大鼠模型,观察NAFLD大鼠是否也同时伴随存在肠道炎症,并探讨NAFLD对肠道通透性的影响。方法 24只雄性大鼠以1∶1比例随机接受标准饲料和高脂饲料喂食18周,分别建立对照组和NAFLD大鼠模型。通过大鼠肝脏病理切片HE染色和油红O染色验证模型的成立,根据大鼠结肠病理切片HE染色观察是否存在肠道炎症进行进一步分组分析。使用酶联免疫吸附测定血浆二胺氧化酶、D-乳酸水平和内毒素水平,检测肠道通透性改变情况。结果与对照组相比,12只NAFLD大鼠肝脏均呈大泡和小泡性脂肪变以及气球样变,其中发现有7只大鼠的肠道存在轻度炎症细胞浸润,组织学符合肠道炎症改变;NAFLD组中另5只大鼠未见组织学上肠道炎症改变;而在对照组中未见任何肠道炎症改变。与对照组相比,NAFLD大鼠血浆中二胺氧化酶和D-乳酸水平显著升高(P0.05)。其中,NAFLD伴肠道炎症组大鼠的D-乳酸水平较NAFLD不伴肠道炎症组显著升高(P0.05)。NAFLD伴肠道炎症组大鼠血浆中LBP水平明显高于对照组和NAFLD不伴肠道炎症组(均P0.05)。结论 NAFLD可增加肠道炎症发生的风险,NAFLD导致肠道炎症时肠道通透性显著增加。     

枯草杆菌肠球菌二联活菌胶囊对非酒精性脂肪性肝炎患者血清内毒素水平的影响

目的探讨枯草杆菌肠球菌二联活菌胶囊对非酒精性脂肪性肝炎(NASH)患者肠道通透性及血清内毒素水平的影响。方法选择健康正常成人30例作为正常对照组和非酒精性脂肪性肝炎患者60例,给予后者枯草杆菌肠球菌二联活菌胶囊治疗4周。检测所有被研究者血清内毒素、二胺氧化酶(DAO)、D-乳酸及ALT水平。结果与对照组比较,治疗前患者内毒素、DAO、D-乳酸水平显著增高【分别为143.60±21.41EU/l对109.78±17.81EU/l(t=7.71,P<0.01);2.6±0.47U/ml对2.3±0.48U/ml(t=2.24,P<0.05);6.1±1.05mg/l对5.3±0.97mg/(l t=4.89,P<0.01)】;NASH患者治疗后与治疗前比较,内毒素、DAO、D-乳酸及ALT水平显著降低。结论非酒精性脂肪性肝炎患者肠道通透性及血清内毒素水平增高,微生态制剂枯草杆菌肠球菌二联活菌胶囊可降低肠道通透性、血清内毒素及ALT水平。     

Effect of lactulose on establishment of a rat non-alcoholic steatohepatitis model

AIM: To explore the relationship between changes of intestinal environment and pathogenesis of non-alcoholic steatohepatitis (NASH). METHODS: Forty-two Sprague-Dawley rats were randomly divided into model group (n = 24), treatment group (n = 12), and control group (n = 6). The rats of model and treatment groups were given high-fat diet, and those of the control group were given normal diet. Furthermore, the rats of treatment group were given lactulose after 8 wk of high-fat diet. Twelve rats of the model group were killed at 8 wk of high-fat diet. At the 16 wk the rats of treatment group, control group, and the rest of the model group were killed. The serum levels of aminotransferase were measured and the histology of livers was observed by H&E staining. RESULTS: The livers of rats presented the pathological features of steatohepatitis with higher serum levels of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the model group after 16 wk. Compared to the model group, the serum levels of ALT and AST in treatment group decreased significantly and were close to the normal group, and the hepatic inflammation scores also decreased markedly than those in the model group after 16 wk (5.83±2.02 vs3.63±0.64, P<0.05), but were still higher than those in the model group after 8 wk (3.63±0.64 vs 1.98±0.90, P<0.05). However, the degree of hepatic steatosis had no changes in treatment group compared to the model group after 16 wk. CONCLUSION: Lactulose could ameliorate the hepatic inflammation of rats with steatohepatitis induced by fat-rich diet, but could not completely prevent the development of steatohepatitis. It is suggested that intestinal environmental changes such as intestinal bacteria overgrowth, are one of the important factors in the pathogenesis of NASH.     

乳果糖降低非酒精性脂肪性肝炎患者肠道通透性及血清内毒素水平

目的探讨乳果糖对非酒精性脂肪性肝炎(non-alcoholic steatohepatitis,NASH)患者肠道通透性的干预作用。方法选择健康正常成人30例作为正常对照组(A组),非酒精性脂肪性肝炎共60例,随机分为NASH对照组(B组)和乳果糖干预组(C组)各30例,其中C组给予乳果糖(10 mL/d)进行干预。检测所有被研究者的血清内毒素、二胺氧化酶(diamine oxidase,DAO)、D-乳酸及ALT的浓度。干预4周后,再次检测B、C两组的血清内毒素、二胺氧化酶(DAO)、D-乳酸及ALT的浓度。结果与A组比较,治疗前B、C两组内毒素、DAO、D-乳酸水平显著增高(P<0.01),B组干预前后比较,内毒素、DAO、D-乳酸及ALT水平无显著改变(P>0.05),而C组干预前后比较,内毒素、DAO、D-乳酸及ALT水平显著降低(P<0.01)。结论 NASH患者血清内毒素水平及肠道通透性增高,乳果糖可降低NASH患者肠道的通透性及血浆内毒素水平。     

Change of intestinal mucosa barrier function in the progress of non-alcoholic steatohepatitis in rats

AIM： To explore the change of intestinal mucosa barrier function in the progress of non-alcoholic steatohepatitis （NASH） in rats. METHODS： Thirty-two Sprague-Dawley （SD） rats were randomly divided into control group and model group. Rats in the control group were given normal diet, and rats in the model group were given fat-rich diet. Eight rats in each group were killed at end of the 8th and 12th wk, respectively. The levels of endotoxin, D-xylose, TG, TC, ALT and AST, intestinal tissue SOD and MDA as well as intestinal mucus secretory IgA （sIgA） were measured. The pathology of liver was observed by HE staining. RESULTS： At end of the 8th wk, there was no marked difference in the levels of endotoxin, D-xylose and sIgA between the two groups. At end of the 12th wk, rats in the model group developed steatohepatitis and had a higher serum level of endotoxin （P = 0.01） and D-xylose （P = 0.00） and a lower serum level of sIgA （P = 0.007）. CONCLUSION： Intestinal mucosa barrier malfunction may exist in NASH rats and may be an important promoter of NASH in rats.     

甘氨酸对NASH大鼠肝组织环氧合酶-2表达的影响

目的 探讨环氧合酶-2在非酒精性脂肪性肝炎发病机制中的作用以及甘氨酸对其表达的影响。方法 选择雄性Wistar大鼠54只,随机分为对照组、高脂饮食组和甘氨酸干预组,比较实验第8、12和16周末动物血浆ALT和内毒素水平及肝组织COX-2的表达情况。结果 在实验第12周和16周末,脂肪肝组动物血浆ALT较对照组明显增高（P〈0．05）,各期脂肪肝组和甘氨酸组动物腹主动脉血内毒素水平与对照组比较均无差异,而门静脉血内毒素水平明显上升,腹主动脉血与相对应的门静脉血内毒素比较有显著性差异（P〈0．01）;在第16周脂肪肝组和甘氨酸组COX-2表达呈阳性,甘氨酸处理组积分光密度值比脂肪肝组明显降低（P〈0．05）;在对照组、实验第8周和12周脂肪肝组肝内无COX-2 mRNA表达,但在第16周脂肪肝组动物肝内COX-2的相对表达量为0．67±0．04,甘氨酸组为0．43±0．04,两者比较有显著性差异（P〈0．05）;血浆内毒素水平与COX-2表达呈正相关（r=0．58,P〈0．01）。结论肠源性内毒素血症上调肝组织COX-2表达,后者在NASH发病机制中起着重要的作用,甘氨酸能降低内毒素水平,并使NASH大鼠肝内COX-2表达减少。     

胰岛素抵抗在非酒精性脂肪肝发病中的作用

目的:探讨胰岛素抵抗(IR)在非酒精性脂肪肝(NAFL)大鼠脂肪肝模型中的作用机制.方法:大鼠随机分为空白对照组,脂肪肝模型对照组(模型+生理盐水组)和脂肪肝实验组(模型+罗格列酮组).其中脂肪肝模型对照组和脂肪肝实验组分别予生理盐水和马来酸罗格列酮干预治疗4wk.观察各组大鼠肝脏大体形态和组织学改变;检测空腹血糖(FPG),空腹血胰岛素水平(FINS),计算胰岛素抵抗指数(IRI);检测血浆ApoCⅡ、ApoCⅢ水平及血浆脂蛋白脂肪酶(LPL)、肝脂肪酶(HL)活性和大鼠肝组织ApoB-100mRNA的表达量.结果:治疗前,脂肪肝组大鼠(包括脂肪肝模型组和脂肪肝实验组)与空白对照组大鼠比较,肝脏组织学改变达到脂肪肝诊断标准,FPG、FINS明显升高(6.46mmol/L±0.75mmol/L,6.61mmol/L±0.45mmol/L vs5.48mmol/L±0.47mmol/L;78.82mU/L±11.13mU/L,78.48mU/L±12.94mU/Lvs40.90mU/L±7.76mU/L),IR也明显升高(22.48±2.81,22.98±3.47vs9.85±1.15),血浆ApoCⅡ水平降低...     

缬沙坦和培哚普利对大鼠肝纤维化模型肠通透性的影响

目的 观察血管紧张素受体阻滞剂缬沙坦和血管紧张素转换酶抑制剂培哚普利对四氯化碳诱导大鼠肝纤维化模型的疗效及对其肠通透性的影响。方法 将大鼠分为A组(正常对照组)、B组(模型对照组)、C组(缬沙坦治疗组)和D组(培哚普利治疗组)，于造模第4周C组开始用缬沙坦(10mg／kg)，D组开始用培哚普利(0.5mg／kg)治疗，共4周，进行肝组织及小肠组织苏木精-伊红染包，检测血浆D乳酸、DAO和内毒素浓度。结果经治疗后肝纤维化大鼠肝小叶结构趋于正常，纤维间隔变薄，血浆D-乳酸、DAO和内毒素浓度下降。结论 培哚普利和缬沙坦能有效地减轻四氯化碳诱导肝纤维化大鼠的损伤及纤维化程度，减轻肠源性内毒素血症和肠通透性增加。     

非酒精性脂肪性肝病大鼠血浆前列环素与血栓素的变化及其与肝脏损伤的关系

目的 探讨非酒精性脂肪性肝病(NAFLD)大鼠血浆前列环素(PG12)和血栓索(TX)A2的动念变化及其与肝组织学改变之间的关系。 方法 48只模型组SD大鼠给予高脂肪高胆固醇饮食饲养,分批于第8、12、16、24周处死,24只正常饮食大鼠作对照。放射免疫法检测血浆PGI 2和TXA 2的稳定代谢产物6酮-前列环素1α(PGF1 α)和TXB2含量,光镜观察肝组织切片病理学改变。 结果 模型组大鼠8周呈现单纯性脂肪肝,12～24周从脂肪性肝炎进展至脂肪性肝纤维化。模型组大鼠血浆TXB 2在造模第8、24周分别为(52.4±3.15)ng/L和(117.7±7.47)ng/L,对照组为(41.1±1.45)ng/L,t值为9.12和31.34,P<0.01和P<0.001。 血浆PGF1 α水平在造模8、24周分别为(31.1±1.6)ng/L和(3.4±2.4)ng/L,对照组为(36.5±1.7)ng/L,t值为6.27和34.62,P<0.01和,P<0.001。模型组大鼠血浆TXB2和PGF1 α水平分别与其肝组织损伤程度呈显著正相关(r=0.537,P<0.001)及负相关(r=-0.452,P<0.01)。 结论 持续24周的高脂饮食可以成功复制大鼠NAFLD模型,模型大鼠血浆TXA 2与PGI 2平衡失调,可能参与NAFLD的发病。     

Effects of ursodeoxycholic acid and／or low-calorie diet on steatohepatitis in rats with obesity and hyperlipidemia

AIM: To evaluate the effects of ursodeoxycholic acid (UDCA) and/or low-calorie diet (LCD) on a rat model of nonalcoholic steatohepatitis (NASH). METHODS: Fifty-five Sprague-Dawley rats were divided into five groups. The control group (n = 9) was fed with standard rat diet for 12 wk, NASH group (n = 10) was fed with high-fat diet consisted of normal diet, 10% lard oil and 2% cholesterol for 12 wk, UDCA group (n = 10) was fed with high-fat diet supplemented with UDCA at a dose of 25 mg/(kg · d) in drinking water for 12 wk, LCD group (n = 10) was fed with high-fat diet for 10 wk and then LCD for 2 wk, and UDCA+LCD group (n = 15) was fed with high-fat diet for 10 wk, followed by LCD+UDCA for 2 wk. At the end of the experiment, body weight, serum biochemical index, and hepatopathologic changes were examined. RESULTS: Compared with the control group, rats in the NASH group had significantly increased body weight, liver weight, and serum lipid and aminotransferase levels. All rats in the NASH group developed steatohepatitis, as determined by their liver histology. Compared with the NASH group, there were no significant changes in body weight, liver weight, blood biochemical index, the degree of hepatic steatosis, and histological activity index (HAI) score in the UDCA group; however, body and liver weights were significantly decreased, and the degree of steatosis was markedly improved in rats of both the LCD group and the UDCA+LCD group, but significant improvement with regard to serum lipid variables and hepatic inflammatory changes were seen only in rats of the UDCA+LCD group, and not in the LCD group. CONCLUSION: LCD might play a role in the treatment of obesity and hepatic steatosis in rats, but it exerts no significant effect on both serum lipid disorders and hepatic inflammatory changes. UDCA may enhance the therapeutic effects of LCD on steatohepatitis accompanied by obesity and hyperlipidemia. However, UDCA alone is not effective in the prevention of steatohepatitis induced by high-fat diet.     

Serum ubiquitin levels in patients with nonalcoholic steatohepatitis

BACKGROUND/AIMS: Nonalcoholic steatohepatitis is increasingly recognized as the most common liver disease in patients with elevated liver enzymes. In the pathophysiology of nonalcoholic steatohepatitis, the first step is the lipid accumulation in the liver causing steatosis, the second step involves the endotoxins, cytokines and environmental toxins causing oxidative stress and lipid peroxidation, in time leading to steatohepatitis. Ubiquitin is a molecular chaperone that plays a major role in the degradation of intracellular proteins. Ubiquitin proteasome system is also considered as a cellular defense mechanism that removes damaged proteins generated by oxidative stress. In order to search for the role of ubiquitin in the pathogenesis of nonalcoholic steatohepatitis, serum levels of ubiquitin were studied in patients with nonalcoholic steatohepatitis for the first time in the literature, to our knowledge. METHODOLOGY: Eighteen patients with biopsy proven nonalcoholic steatohepatitis diagnosis (13 males and 5 females with a mean age of 41) and 16 healthy volunteers as a control group (11 males and 5 females, with a mean age of 38) were included in the study. Serum ubiquitin levels were studied by ELISA method. RESULTS: The mean serum ubiquitin level (14.13 +/- 1.46 micrograms/mL) in patients with nonalcoholic steatohepatitis was significantly elevated compared to that of the control group (7.66 +/- 0.40 micrograms/mL) (p < 0.001). No correlation was found among serum ubiquitin levels and hepatic steatosis, inflammation and fibrosis. CONCLUSIONS: Increased serum ubiquitin levels may show that the ubiquitin proteasome pathway actively participates in defending against oxidative stress in nonalcoholic steatohepatitis. Serum ubiquitin concentration may be a marker predicting the intracellular cytoprotective response against oxidative stress rather than the degree of liver damage in pathogenesis of nonalcoholic steatohepatitis. Ubiquitin proteasome system based therapies may have a place in the treatment of patients with nonalcoholic steatohepatitis in the future.     

Dynamic alterations in the gut microbiota and metabolomeduring the development of methionine-choline-deficient diet-induced nonalcoholic steatohepatitis

AIM To investigate changes in gut microbiota and metabolism during nonalcoholic steatohepatitis(NASH) development in mice fed a methionine-choline-deficient(MCD) diet. METHODS Twenty-four male C57 BL/6 J mice were equally divided into four groups and fed a methionine-choline-sufficient diet for 2 wk(Control 2 w group,n = 6) or 4 wk(Control 4 w group,n = 6) or the MCD diet for 2 wk(MCD 2 w group,n = 6) or 4 wk(MCD 4 w group,n = 6). Liver injury,fibrosis,and intestinal barrier function were evaluated after 2 and 4 wk of feeding. The fecal microbiome and metabolome were studied using 16 s r RNA deep sequencing and gas chromatography-mass spectrometry. RESULTS The mice fed the MCD diet presented with simple hepatic steatosis and slight intestinal barrier deterioration after 2 wk. After 4 wk of feeding with the MCD diet,however,the mice developed prominent NASH with liver fibrosis,and the intestinal barrier was more impaired. Compared with the control diet,the MCD diet induced gradual gut microbiota dysbiosis,as evidenced by a marked decrease in the abundance of Alistipes and the(Eubacterium) coprostanoligenes group(P 0.001 and P 0.05,respectively) and a significant increase in Ruminococcaceae UCG 014 abundance(P 0.05) after 2 wk. At 4 wk,the MCD diet significantly reduced the promising probiotic Bifidobacterium levels and markedly promoted Bacteroides abundance(P 0.05,and P 0.01,respectively). The fecal metabolomic profile was also substantially altered by the MCD diet: At 2 wk,arachidic acid,hexadecane,palmitic acid,and tetracosane were selected as potential biomarkers that were significantly different in the corresponding control group,and at 4 wk,cholic acid,cholesterol,arachidic acid,tetracosane,and stearic acid were selected. CONCLUSION The MCD diet induced persistent alterations in the gut microbiota and metabolome.     

髓系细胞触发受体-1在非酒精性脂肪性肝炎中的作用

目的：研究探讨肝脏髓系细胞触发受体-1（triggering receptor expressed on myeloid cells-1,TREM-1）在非酒精性脂肪性肝炎发生发展中的作用。方法：雄性SD大鼠24只,自由饮食,自然光照,环境温度17～23℃,适应性饲养1周后随机分成两组：对照组（普通饲料喂养＋腹腔注射生理盐水）,模型组（高脂饮食＋腹腔注射氧四环素）,造模4周、8周时分批处死,按照实验要求采集腹主动脉血并检测血浆中的肿瘤坏死因子-α（TNF-α）、谷氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、白细胞介素-6（IL-6）、白细胞介素-10（IL-10）和门静脉血浆内毒素（ET）水平;取肝标本做HE染色,并用ELISA方法检测肝脏TREM-1的表达量。结果：与同期对照组相比,4周时模型组TNF-α、ALT、AST、ET明显升高（P〈0.05）;与对照组比较8周时模型组大鼠IL-6明显升高（P〈0.05）;4周起模型组大鼠IL-10开始降低（P〈0.05）;ELISA结果显示4周、8周模型组TREM-1的表达量与同期对照组相比差异均有显著性意义（P〈0.05）;直线相关分析结果：TREM-1与TNF-α、ET、IL-6均呈正相关,与IL-10呈负相关（P〈0.01）。结论：TREM-1通过与肠源性内毒素血症（IETM）的相互作用在非酒精性脂肪性肝炎的发生与发展中起有重要作用。     

Prevalence of the hemochromatosis gene mutation in patients with nonalcoholic steatohepatitis and correlation with degree of liver fibrosis

BACKGROUND: Nonalcoholic steatohepatitis is a chronic liver disease with a high prevalence in the general population and a potential to evolve into cirrhosis. It is speculated that iron overload could be associated with liver injury and unfavorable progress in affected patients. AIMS: To evaluate the prevalence of mutation of the hemochromatosis gene (HFE) in patients with nonalcoholic steatohepatitis and to correlate it with histological findings in liver specimens. PATIENTS AND METHODS: Twenty-nine patients with nonalcoholic steatohepatitis were evaluated. The presence of mutation in the hemochromatosis gene (C282Y and H63D) was tested in all patients and its result was evaluated in relation to hepatic inflammatory activity, presence of fibrosis, and iron overload in the liver. The control group was composed of 20 patients with normal liver function tests and 20 patients infected with the hepatitis C virus, with elevated serum levels of aminotransferases and with chronic hepatitis as shown by biopsy. RESULTS: Mutation of the hemochromatosis gene (C282Y and/or H63D) was diagnosed in 16 (55.2%) patients with nonalcoholic steatohepatitis, in 12 (60%) patients with hepatitis C and in 8 (40%) patients with no liver disease. No association was found between the presence of mutation and inflammatory activity, nor with the presence of fibrosis in patients with nonalcoholic steatohepatitis. An association was found between the presence of mutation and the occurrence of iron overload in liver, but there was no association between liver iron and the occurrence of fibrosis. CONCLUSIONS: The findings suggest that iron does not play a major role in the pathogenesis and progression of nonalcoholic steatohepatitis, and routine tests of the hemochromatosis gene mutation in these patients should not be recommended.     

Obesity and related parameters of non-alcoholic steatohepatitis.

BACKGROUND/AIMS: The aim of this prospective study was to evaluate the clinical, biochemical and histopathological parameters of nonalcoholic steatohepatitis and the conditions associated with this disease. METHODS: Twenty-four patients were included in the study, each having been diagnosed with nonalcoholic steatohepatitis on the basis of liver biopsy and elimination of other possible causes of elevated aminotransferase levels. Measurements of degree of obesity, liver enzymes and serum lipids were recorded before liver biopsy and reevaluated after one or two months of a standard exercise and diet program. Serum insulin levels were also measured. Each liver biopsy was histologically examined for steatosis, inflammation, fibrosis, necrosis and iron storage, and semiquantitave assessment of these was recorded for three separate hepatic zones. RESULTS: The prevalence of obesity in the group was 79.2%, while the figure for overt and latent diabetes mellitus combined was 33.3%, and for hyperlipidemia was 83.3%. Compared to the rest of the group, the patients with severe steatosis had significantly higher serum lipid (particularly high triglyceride) and insulin levels (p<0.05 for both). There was a correlation between steatosis and obesity (p=0.06). More severe obesity, higher insulin and elevated aspartate aminotransferase were positively correlated with inflammation, whereas elevated serum triglyceride was negatively correlated with inflammation. There was a tendency towards normalization of liver enzyme levels after weight loss and dietary restrictions. CONCLUSIONS: Obesity and hyperlipidemia were associated with nonalcoholic steatohepatitis in the group studied. Obesity is not a factor in every case, but the study showed that restricted diet and exercise are significant forms of therapy for nonalcoholic steatohepatitis.     

疏肝祛瘀通络降浊法对大鼠非酒精性脂肪性肝炎作用的研究

[目的]观察疏肝祛瘀通络降浊法对非酒精性脂肪性肝炎（NASH）大鼠肝组织髓样分化蛋白-2（MD-2）和诱导型一氧化氮合酶（iNOS）基因表达的影响,以探讨二者在NASH发病中的作用。[方法]雄性SD大鼠分为模型组,疏肝祛瘀通络降浊法低剂量（低剂量）组、中剂量组、高剂量组,阳性对照组,预防组和正常组,除正常组外,其余各组大鼠以高脂饮食喂养4周后用不同剂量的中药和阳性对照药灌胃治疗,12周后全部处死。同期设正常饮食组作为对照。免疫组织化学方法观察肝组织核转录因子-κB（NF-κB）表达,逆转录聚合酶链反应（RT-PCR）法观察肝组织MD-2和iNOS mRNA的表达。[结果]12周时,中剂量组大鼠肝组织NF-κB表达较模型组下调;肝组织MD-2mRNA（0.132±0.058）和iNOS mRNA（0.164±0.061）表达较模型组（0.795±0.294和1.029±0.388）减弱（均P〈0.01）。[结论]大鼠NASH形成后,肝组织MD-2和iNOS mRNA的表达上调,可能与二者参与了NASH大鼠内毒素性肝损伤有关。疏肝祛瘀通络降浊法可以通过减轻内毒素性肝损伤下调NASH大鼠肝组织MD-2和iNOSmRNA的表达。     

非酒精性脂肪性肝炎大鼠肠道分泌液sIgA的变化

目的探讨非酒精性脂肪性肝炎形成过程中小肠分泌液sIgA和血浆内毒素水平的变化。方法 32只SD大鼠随机均分为对照组和模型组,对照组用普通饲料喂养,模型组通过高脂饮食建立大鼠非酒精性脂肪性肝炎（non-alcoholic steatohepatitis,NASH）模型,并分别在8、12周末处死每组大鼠各8只,测定大鼠小肠分泌液中sIgA的水平和门静脉血浆中内毒素水平,测定小肠组织匀浆中SOD的活性和MDA的含量,并测定大鼠血清中TG、TC、ALT、AST,HE染色观察肝脏病理改变。结果 8、12周模型组较正常对照组大鼠血清TC、ALT、AST明显升高（P〈0.05）,肝脏病理分别表现为单纯性脂肪肝、脂肪性肝炎。8周末时模型组大鼠门静脉血浆中内毒素、小肠分泌液中sIgA的水平与对照组相比无明显变化（P〉0.05）;12周末大鼠NASH阶段与对照组相比小肠分泌液中sIgA的水平明显降低（P〈0.05）,门静脉血浆中内毒素水平与对照组相比明显升高（P〈0.05）。并且门静脉血浆内毒素水平与小肠分泌液中sIgA水平呈负相关（r=-0.873,P〈0.05）。8、12周末时模型组大鼠小肠组织匀浆中SOD活性明显降低,MDA含量明显升高（P〈0.05）。结论非酒精性脂肪性肝炎形成过程中小肠分泌液中sIgA明显降低,说明肠道免疫屏障受损,并且可能与肠道脂质过氧化增强有关,可能是NASH发生发展的重要发病机制之一。     

酒精性肝炎小鼠肝肠组织变化与内毒素血症的关系探讨

目的酒精性肝病常伴发肠源性内毒素血症,但两者孰因孰果尚不明确。本研究的目的是探讨肠源性内毒素血症与酒精性肝病的关系。方法 20只C57BL/6小鼠被随机分为对照组和模型组,采用饲喂Lieber-Decarli无酒精和含酒精液体法制备酒精性肝炎模型。6周后取小鼠肝脏和结肠组织进行病理学观察;采用酶联免疫吸附法检测血清内毒素、二胺氧化酶和D乳酸含量;采用高效液相色谱法分析尿中乳果糖和甘露醇含量比值,以动态观察小鼠肠道通透性的变化。结果模型组动物肝细胞明显脂肪变,说明模型制备成功;模型组动物结肠粘膜变薄,萎缩,肠上皮细胞脱落,病理学评分(3.41±0.59)与对照组(2.36±0.43)比,差异有统计学意义(P=0.04);模型组和对照组动物血清内毒素水平分别为0.40±0.07Eu/L和0.14±0.03Eu/L(P=0.02),二胺氧化酶分别为4.17±0.88 U/mL和2.09±0.39U/mL(P=0.03),D乳酸分别为8.53±1.10mg/L和6.58±1.00mg/L(P=0.04),差异均有统计学意义;模型组小鼠1~6周末尿乳果糖/甘露醇(L/M值)排泄率分别是2.28±0.33(P>0.05)、2.55±0.40、2.49±0.18、2.51±0.55、2.46±0.59和2.59±0.44,对照组则分别是2.16±0.30、2.34±0.33、2.27±0.24、2.01±0.27、2.24±0.26和2.17±0.31,后5周两组比,均有显著性差异(P<0.05)。结论肠道通透性的增加早于肝脏损伤,肠道通透性增加引起的内毒素血症是酒精性肝炎的关键诱发因素。     

Trimethylamine N-oxide attenuates high-fat high-cholesterol dietinduced steatohepatitis by reducing hepatic cholesterol overload in rats

BACKGROUND Trimethylamine N-oxide (TMAO) has been shown to be involved in cardiovascular disease (CVD). However, its role in nonalcoholic steatohepatitis (NASH) is unknown. AIM To determine the effect of TMAO on the progression of NASH. METHODS A rat model was induced by 16-wk high-fat high-cholesterol (HFHC) diet feeding and TMAO was administrated by daily oral gavage for 8 wk. RESULTS Oral TMAO intervention attenuated HFHC diet-induced steatohepatitis in rats. Histological evaluation showed that TMAO treatment significantly alleviated lobular inflammation and hepatocyte ballooning in the livers of rats fed a HFHC diet. Serum levels of alanine aminotransferase and aspartate aminotransferase were also decreased by TMAO treatment. Moreover, hepatic endoplasmic reticulum (ER) stress and cell death were mitigated in HFHC diet-fed TMAOtreated rats. Hepatic and serum levels of cholesterol were both decreased by TMAO treatment in rats fed a HFHC diet. Furthermore, the expression levels of intestinal cholesterol transporters were detected. Interestingly, cholesterol influxrelated Niemann-Pick C1-like 1 was downregulated and cholesterol efflux-related ABCG5/8 were upregulated by TMAO treatment in the small intestine. Gut microbiota analysis showed that TMAO could alter the gut microbial profile and restore the diversity of gut flora. CONCLUSION These data suggest that TMAO may modulate the gut microbiota, inhibit intestinal cholesterol absorption, and ameliorate hepatic ER stress and cell death under cholesterol overload, thereby attenuating HFHC diet-induced steatohepatitis in rats. Further studies are needed to evaluate the influence on CVD and define the safe does of TMAO treatment.     

疏肝祛瘀通络降浊法对大鼠非酒精性脂肪性肝炎的保护作用

目的探讨非酒精性脂肪性肝炎大鼠内毒素性肝损伤机制及中药对其影响。方法用喂饲高脂饮食的方法建立非酒精性脂肪性肝炎大鼠模型。4周后用疏肝祛瘀通络降浊法分小、中、大剂量进行治疗,12周后处死测定血脂、ALT、内毒素(ET)、肿瘤坏死因子(TNF-α)和白细胞介素(IL-1β)的含量;免疫组化法观察肝组织CD14和核转录因子(NF-κB)的表达;RT-PCR检测脂多糖结合蛋白(LBP)和4型Toll样受体(TLR-4)mRNA的表达。同期正常饮食饲养大鼠作对照。结果第12周时,模型组大鼠腹主动脉血清内毒素水平较正常组明显升高,有显著性差异;中剂量治疗组大鼠血清ET、TNF-α、IL-1β水平明显低于模型组,差异有显著意义。模型组大鼠肝组织CD14阳性细胞数量明显增多,主要分布于肝窦内,部分呈灶型聚集;与模型组相比,中剂量治疗组大鼠肝组织CD14阳性细胞数量明显减少。模型组可见少量细胞核染色的NF-κB阳性细胞散在分布于汇管区。模型组肝组织LBPmRNA和TLR-4mRNA表达均明显上调,与正常组比较差异均有显著意义;中剂量治疗组大鼠肝组织LBPmRNA和TLR-4mRNA表达均较模型组明显下调,且有显著性差异。结论疏肝祛瘀通络降浊法对非酒精性脂肪肝有疗效,可能与其降低血清内毒素水平和下调肝组织内毒素相关受体表达继而减轻炎症性肝损害有关。