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1.
ObjectiveTo explain the role of oxidative stress in the pathology of celiac disease.Design and methodsThe activities of antioxidant enzymes and the levels of glutathione and lipid hydroperoxides were measured in the samples of small intestinal biopsies from 39 children with different forms of the disease and in 19 control subjects.ResultsThe activities of analyzed enzymes varied significantly between the examined groups. An increase in the activities of superoxide dismutase was observed in patients with active and silent celiac disease, while the activities of glutathione peroxidase and glutathione reductase and the glutathione content were significantly reduced. The level of lipid hydroperoxides was significantly elevated in these groups.ConclusionsOxidative stress is an important factor in the pathogenesis of celiac disease. The antioxidant capacity of celiac patients is significantly reduced, mostly by a depletion of glutathione. Natural antioxidants and appropriate dietary supplements could be important complements to the classic therapy of celiac disease.  相似文献   

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Epithelial cell renewal of the small intestinal mucosa   总被引:1,自引:0,他引:1  
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保护早产儿胃肠道黏膜功能的研究进展   总被引:6,自引:0,他引:6  
近年来,随着对胃肠道黏膜屏障功能不断深入的研究,肠内营养尤其是早期肠内营养越来越受到医学界的普遍关注。对于早产儿,由于各系统发育尚不完善,胃肠道功能不健全的特点,如何更好地保护胃肠道黏膜功能,更科学的营养支持已成为临床研究的重要课题。本文就此方面的研究进展综述如下。1保护早产儿胃肠道黏膜的意义随着分子生物学的研究,证实了肠道屏障功能对危重疾病的发生、发展和转归起着极为重要的作用。1988年Mar-shall认为肠原性感染可能是多脏器功能衰竭的启动器官,可见肠道是全身器官的“受损门户”,它与许多内脏功能有密切的联系[1]…  相似文献   

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Abstract The effect of dietary factors and experimental manipulations designed to perturb the entero-hepatic circulation on the rate of sterol synthesis were studied in freshly isolated human jejunal mucosa from normal subjects.
Fasting significantly reduced the rate of sterol synthesis from [14C] acetate in jejunal mucosa obtained from normolipaemic obese subjects. A high cholesterol diet had no consistent effect on the synthesis in normal subjects. Administration of cholestyramine resulted in a marked rise in the incorporation of [l4C] acetate into sterols, while the administration of chenodeoxycholic acid did not significantly reduce basal sterol synthesis in normal subjects.
These results demonstrate that in man the rate of sterol synthesis in intestinal mucosa is altered in response to physiological variables. Although these findings indicate that sterol synthesis in this tissue is subject to regulation, no difference was observed in basal sterol synthesis between normal subjects and patients heterozygous for familial hypercholesterolaemia.  相似文献   

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Abstract. The effect of dietary factors and experimental manipulations designed to perturb the entero-hepatic circulation on the rate of sterol synthesis were studied in freshly isolated human jejunal mucosa from normal subjects.
Fasting significantly reduced the rate of sterol synthesis from [14C] acetate in jejunal mucosa obtained from normolipaemic obese subjects. A high cholesterol diet had no consistent effect on the synthesis in normal subjects. Administration of cholestyramine resulted in a marked rise in the incorporation of [14C] acetate into sterols, while the administration of chenodeoxycholic acid did not significantly reduce basal sterol synthesis in normal subjects.
These results demonstrate that in man the rate of sterol synthesis in intestinal mucosa is altered in response to physiological variables. Although these findings indicate that sterol synthesis in this tissue is subject to regulation, no difference was observed in basal sterol synthesis between normal subjects and patients heterozygous for familial hypercholesterolaemia.  相似文献   

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This work evaluates the feasibility of monitoring ischemic injury in the gastrointestinal mucosa by impedance spectroscopy, using a minimally invasive intestinal catheter. The disruption of the intestinal mucosa plays a key role in the evolution of shock and is the 'motor of multiple organ failure'. Different technologies have been developed to monitor mucosal perfusion, oxygenation and/or ischemia, but no practical method exists to assess tissue damage, which may be crucial for preventing multiple organ failure. The experimental protocol of this study relied on an isobaric model of hypovolemic shock in 16 anaesthetized rabbits assigned to three groups: sham (n = 6), ischemia (n = 5) and ischemia + reperfusion (n = 5). Complex impedance spectra were recorded in the range of 0.05 to 300 kHz, with simultaneous measurements of tonometric pHi in the ileum every 30 min for 4 h. Impedance spectra were reproducible, and those of tissue under prolonged ischemia were clearly differentiable from those of normally perfused tissue. The dynamic changes in impedance did not correlate directly with either tissue perfusion or pHi, but instead correlated well with the duration of ischemia. It is concluded that impedance spectroscopy does indeed measure changes in tissue injury, and could be a very useful tool to guide therapy of patients in shock.  相似文献   

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Amosite asbestos fibers suspended in saline were placed in an isolated segment of rat jejunum in vivo. One hour later, segments of jejunal mucosa were taken for examination in three of the five rats exposed to the amosite suspension. Fibers also were presented in the lamina propria.  相似文献   

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Vasoactive intestinal peptide in human nasal mucosa.   总被引:4,自引:1,他引:4       下载免费PDF全文
Vasoactive intestinal peptide (VIP), which is present with acetylcholine in parasympathetic nerve fibers, may have important regulatory functions in mucous membranes. The potential roles for VIP in human nasal mucosa were studied using an integrated approach. The VIP content of human nasal mucosa was determined to be 2.84 +/- 0.47 pmol/g wet weight (n = 8) by RIA. VIP-immunoreactive nerve fibers were found to be most concentrated in submucosal glands adjacent to serous and mucous cells. 125I-VIP binding sites were located on submucosal glands, epithelial cells, and arterioles. In short-term explant culture, VIP stimulated lactoferrin release from serous cells but did not stimulate [3H]glucosamine-labeled respiratory glycoconjugate secretion. Methacholine was more potent than VIP, and methacholine stimulated both lactoferrin and respiratory glycoconjugate release. The addition of VIP plus methacholine to explants resulted in additive increases in lactoferrin release. Based upon the autoradiographic distribution of 125I-VIP binding sites and the effects on explants, VIP derived from parasympathetic nerve fibers may function in the regulation of serous cell secretion in human nasal mucosa. VIP may also participate in the regulation of vasomotor tone.  相似文献   

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Transport of [D-Ala2, D-Leu5]enkephalin (DADLE(], Tyr-D-Ala-Gly-Phe (TDAGP) and tyrosine into rat jejunum mucosal cells was investigated in vitro. Active transport of either the pentapeptide (DADLE) or the tetrapeptide (TDAGP) into jejunal villi was not detected. Because substantial degradation of these peptides occurred during incubation, the proteolytic enzyme inhibitors, bestatin (30 microM) or D-phenylalanine (20 mM), were added during uptake studies of DADLE or TDAGP, respectively. The presence of these inhibitors significantly reduced degradation of the oligopeptides; however, no accumulation of peptides occurred in the mucosal tissue. Tyrosine was actively transported by the jejunum mucosal cells demonstrating the viability of the transport mechanisms of this in vitro preparation. The results suggest that there are no active transport systems for enkephalin-like oligopeptides.  相似文献   

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目的 研究肠上皮化生胃黏膜组织中p21^ras、表皮生长因子受体(EGFR)和p53突变蛋白的表达状况及其意义。方法 应用免疫组织化学方法对44例肠上皮化生组织、10例正常胃黏膜和31例胃癌组织中p21^ras、EGFR和p53突变蛋白的表达进行同步检测。结果 44例肠上皮化生组织中,p21^ras、EGFR和p53突变蛋白的表达阳性率分别为59.1%、54.6%和20.5%;31例胃癌组织中,p21^ras、EGFR和p53突变蛋白的表达阳性率分别为64.5%、54.8%和32.3%;肠上皮化生组织和胃癌组织间3种基因蛋白的表达阳性率差异无显著性(P〉0.05)。结论 肠上皮化生胃黏膜组织中存在多种基因的表达异常,值得深入研究。  相似文献   

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目的 观察组织胺对肠黏膜免疫分泌的调节作用.方法 从十二指肠灌注大肠杆菌制成单纯感染模型,从颈静脉插管放血加十二指肠灌注大肠杆菌制成失血感染模型.大鼠随机分为假手术组、单纯感染组、失血感染组和1×10-6 mol/L浓度的组织胺对以上各组的干预组共6组.组织胺干预组分别用1×10-6 mmol/L的组织胺对制成的模型大鼠进行肠内灌注.观察模型大鼠免疫球蛋白IgA分泌量.结果 1×10-6 mmol/L组织胺干预组肠道IgA分泌量较失血-感染组也明显增多(P<0.05).结论 一定剂量的组织胺能增强肠黏膜的免疫屏障功能,抑制细菌移位.  相似文献   

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大黄对大鼠肠粘膜及肠血管通透性的影响   总被引:62,自引:3,他引:62  
目的:研究大黄对肠粘膜及肠血管通透性的影响。方法:选用低血容量性休克和内毒素性休克大鼠动物模型,以荧光标记白蛋白和小肠湿/干重比值检测内毒素性休克肠血管通透性,以血浆内毒素含量来衡量肠粘膜通透性。结果:内毒素能引起小肠组织明显水肿,其湿/干重比值显著增高,同时明显提高肠血管壁对荧光标记白蛋白的通透性;而大黄能减轻肠壁水肿和湿/干重比值(内毒素组为3.75±0.68,大黄组为1.66±0.33,P<0.01),降低肠血管通透性〔小肠组织荧光标记白蛋白含量:内毒素组为(1.254±0.117)μmol/g,大黄组为(0.900±0.071)μmol/g,P<0.01〕。低血容量性休克能破坏肠粘膜屏障,提高肠粘膜对内毒素的通透性,而大黄可明显降低低血容量性休克大鼠肠粘膜通透性,抑制肠道内毒素的吸收〔血浆内毒素含量:休克组为(0.557±0.069)EU/ml,大黄组为(0.345±0.055)EU/ml,P<0.01〕。结论:大黄能保护肠粘膜屏障,抑制肠道内毒素吸收,降低肠粘膜及肠毛细血管通透性。  相似文献   

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目的:非酒精性脂肪性肝病( NAFLD)与肠道屏障功能受损密切相关,本研究探讨非酒精性脂肪肝时肠上皮紧密连接蛋白Zonula Occluden-1(ZO-1)和Occludin的表达变化及其在肠黏膜屏障功能减退中的作用。方法30只雄性SD大鼠随机分为对照组(普通饮食)和高脂模型组,分别于造模的12周、16周检查肝指数(肝湿重/体重)、血清丙氨酸氨基转移酶( ALT)、血清胆固醇( TC)、甘油三酯( TG)、肝组织匀浆丙二醛( MDA)和超氧化物歧化酶( SOD)水平,光镜下观察末端回肠黏膜形态,透射电镜下观察小肠上皮细胞紧密连接超微结构,免疫组化方法检测小肠紧密连接蛋白ZO-1和Occludin的表达。结果16周模型组大鼠肝脏脂肪变性明显,肝指数[(6.3±0.18)% vs.(5.8±0.12)%]、血清 ALT [(68.61±12.12) U/L vs.(25.10±9.06)U/L]、血 TG[(1.30±0.14)mmol/L vs.(0.72±0.06)mmol/L]和肝组织匀浆 MDA 水平[(6.02±0.92)μmol/g vs.(2.15±0.66)μmol/g]均显著高于对照组(P<0.01),肝组织匀浆SOD水平显著低于对照组[(5.12±1.88)U/g vs.(10.52±2.2)U/g,P<0.01];模型组大鼠末端回肠黏膜形态和小肠上皮细胞紧密连接超微结构未见明显异常,但肠上皮细胞凋亡增加。与对照组比较,16周模型组大鼠小肠ZO-1及Occludin蛋白的表达皆显著下降(0.65±0.12 vs.1.08±0.08;0.62±0.08 vs.0.95±0.10, P <0.01)。结论非酒精性脂肪肝时肠黏膜上皮屏障功能减退可能与小肠上皮细胞紧密连接蛋白ZO-1和Occludin的表达异常有关。  相似文献   

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BACKGROUND:

Sepsis has become the greatest threat to in-patients, with a mortality of over 25%. The dysfunction of gut barrier, especially the immunological barrier, plays an important role in the development of sepsis. This dysfunction occurs after surgery, but the magnitude of change does not differentiate patients with sepsis from those without sepsis. Increased intestinal permeability before surgery is of no value in predicating sepsis. The present study aimed to observe the changes of intestinal mucosal immunologic barrier in rat models of sepsis induced by cecal ligation and puncture.

METHODS:

Sixty Sprague-Dawley rats were randomly divided into a sepsis group (n=45) and a control group (n=15). The rats in the sepsis group were subjected to cecal ligation and puncture (CLP), whereas the rats in the control group underwent a sham operation. The ileac mucosa and segments were harvested 3, 6 and 12 hours after CLP, and blood samples were collected. Pathological changes, protein levels of defensin-5 (RD-5) and trefoil factor-3 (TFF3) mRNA, and lymphocytes apoptosis in the intestinal mucosa were determined. In an additional experiment, the gut-origin bacterial DNA in blood was detected.

RESULTS:

The intestinal mucosa showed marked injury with loss of ileal villi, desquamation of epithelium, detachment of lamina propria, hemorrhage and ulceration in the sepsis group. The expression of TFF3 mRNA and level of RD-5 protein were decreased and the apoptosis of mucosal lymphocyte increased (P<0.05) in the sepsis group compared with the control group. Significant differences were observed in RD-5 and TFF3 mRNA 3 hours after CLP and they were progressively increased 6 and 12 hours after CLP in the sepsis group compared with the control group (P<0.05, RD-5 F=11.76, TFF3 F=16.86 and apoptosis F=122.52). In addition, the gut-origin bacterial DNA detected in plasma was positive in the sepsis group.

CONCLUSION:

The immunological function of the intestinal mucosa was impaired in septic rats and further deteriorated in the course of sepsis.KEY WORDS: Sepsis, Mucosal immunology, Defensin-5, Trefoil factor family 3, Cecal ligation and puncture  相似文献   

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