严重烫伤大鼠胃黏膜一氧化氮合酶和环氧合酶-2表达变化及其与热休克蛋白70的关系

本研究通过检测严重烧伤大鼠胃黏膜一氧化氮合酶(NOS)、环氧合酶(COX-2)、热休克蛋白70(HSP70)表达变化,并通过热休克预处理诱导HSP70过量表达,探讨诱导型NOS(iNOs)、COX-2在烧伤大鼠急性胃黏膜病变(AGML)中的可能作用及其与热休克蛋白70的关系.     

替普瑞酮对烧伤大鼠胃黏膜热休克蛋白和诱生型一氧化氮合酶表达的影响

替普瑞酮是树木浆液中含有的萜烯衍生物，具有组织修复作用，据文献报道替普瑞酮可诱导产生热休克蛋白(HSP)，以往的研究多集中于其对乙醇、束缚水浸应激、幽门螺杆菌等引起的胃黏膜损害。本研究通过建立烧伤大鼠急性胃黏膜损伤模型，观察替普瑞酮对严重烧伤大鼠胃黏膜HSP60、HSP70和诱生型一氧化氮合酶(iNOS)表达的影响，探讨其保护作用和机制。     

预处理对老年鼠脑缺血bcl-2表达及细胞凋亡的影响

目的观察缺血预处理对脑缺血再灌注损伤的保护作用。方法将SD老年大鼠分为2组缺血预处理10min再灌注24h再次缺血24h组(PI)及单纯缺血对照组(CI),采用尼龙线栓法制作大鼠局灶性脑缺血模型,通过免疫组化染色技术及原位末端标记技术(TUNEL)检测大鼠大脑皮质bcl-2蛋白的表达和细胞凋亡情况。结果PI组较CI组缺血皮层bcl-2蛋白表达明显增强(P<0.01)。PI组缺血皮层凋亡细胞较CI组明显减少(P<0.05)。结论缺血预处理使缺血脑组织bcl-2蛋白表达增强,抑制凋亡细胞产生,说明缺血预处理对再次脑缺血有保护作用。     

七氟醚和缺血预处理对大鼠血清MDA和肝脏组织HSP70表达的影响

目的 探讨七氟醚预处理和缺血预处理对大鼠血清丙二醛(MDA)和肝脏组织热休克蛋白70(HSP70)表达的影响.方法 32只健康的Wistar大鼠,在肝脏缺血再灌注(IR)前,随机分为正常对照组、IR组、缺血预处理组和七氟醚预处理组,用免疫组化染色检测肝组织HSP70的表达并进行图像分析,采用TAB法检测血清MDA.结果 七氟醚预处理组和缺血预处理组HSP70表达均显著高于IR组和正常对照组(P＜0.01),IR组的HSP70表达略高于正常对照组,七氟醚预处理组和缺血预处理组间的HSP70表达差异无显著性(P＞0.05),而血清MDA水平与HSP70表达呈负相关.结论 七氟醚预处理和缺血预处理均可通过抑制氧自由基的爆发和诱导大鼠肝组织HSP70的高表达而起到保护肝脏免受IR的损伤.     

P16、细胞周期蛋白D1在大鼠胃黏膜萎缩过程中的表达变化及意义

目的研究慢性刺激所致大鼠萎缩性胃炎胃黏膜中P16,细胞周期蛋白D1(Cyclin D1)表达情况。方法采用氨水、脱氧胆酸钠、酒精三因素联合作用制作萎缩性胃炎模型。胃黏膜组织分别行常规HE染色及免疫组织化学染色,免疫组化结果通过图像分析检测。结果模型组胃黏膜出现明显胃窦胃黏膜萎缩。在萎缩过程中,P16表达逐渐下降,Cyclin D1表达逐渐增强,其中,Cyclin D1表达于实验开始后2个月即明显高于对照组(P<0.01),中重度萎缩性胃炎较未萎缩组及轻度萎缩组阳性表达面积均明显高(P<0.01)。P16在6个月实验组的表达阳性面积与同期对照组有减少(P<0.05),中重度萎缩与未萎缩组比较阳性面积明显减少(P<0.01)。结论多因素长期慢性损伤可致大鼠胃黏膜萎缩,大鼠萎缩性胃炎胃黏膜细胞P16蛋白表达低下和Cyclin D1蛋白高表达,存在细胞增殖调控异常,是萎缩性胃炎发病及癌变的分子机制之一。     

葛根素对大鼠心肌缺血再灌注后热休克蛋白70表达的影响

目的探讨葛根素对大鼠心肌缺血再灌注后热休克蛋白70(HSP70)表达的影响。方法结扎大鼠左冠状动脉前降支建立心肌缺血/再灌注模型,运用免疫组化法观察心肌细胞HSP70表达情况及血清髓过氧化物酶(MPO)活性。结果与对照组相比,葛根素组于心肌缺血/再灌注后0.5、4、8h时间点显著上调HSP70表达(P<0.01),抑制血清MPO活性(P<0.01)。结论葛根素可明显减轻心肌缺血再灌注损伤,其心肌保护机制可能是通过上调HSP70的表达、降低血清MPO的活性来实现的。     

热休克蛋白70对过氧化氢所致乳鼠心肌细胞核仁损伤的保护作用

为探讨氧化应激时体外培养的新生Wistar大鼠心肌细胞核仁损伤以及热休克蛋白70对损伤核仁的保护作用。用0.5mmol/L过氧化氢处理原代培养的心肌细胞0,30,60min，采用甲苯胺兰染色核仁及电镜技术观察核仁结构的改变；并通过热休克预处理及反义技术诱导或阻断热休克蛋白70的表达，观察其对核仁损伤的保护作用。结果发现，光镜下过氧化氢损伤组心肌细胞核仁染色颗粒数增多，电镜下核仁结构松散，核仁组份分离。热休克预处理导致心肌细胞中热休克蛋白70表达明显增加，并使过氧化氢缺致心肌细胞核仁损伤明显减轻，免疫组织化学显示过氧化氢可引起热休克蛋白70从胞浆到胞核，再到核仁的移位，热休克蛋白70反义寡核苷酸很大程度上能阻断热休克预处理对心肌细胞核仁损伤的保护作用。结果提示，过氧化氢可导致体外培养的新生大鼠心肌细胞核仁结构损伤，热休克蛋白70高表达及其向核仁的移位对上述损伤具有明显保护作用。     

褪黑激素对应激性溃疡大鼠胃黏膜诱生型一氧化氮合酶表达的影响

背景胃黏膜诱生型一氧化氮合酶(iNOS)的过度表达在应激性溃疡的发生中起重要作用。目的研究褪黑激素(MT)对水浸鄄束缚应激大鼠胃黏膜iNOS表达的影响及其对胃黏膜的保护作用,以进一步阐明MT的作用机制。方法正常对照组不予水浸鄄束缚应激和MT预防,模型组和MT低剂量预防组、MT高剂量预防组于应激前30min分别腹腔注射含1%二甲基亚砜(DMSO)或MT5mg/kg、20mg/kg的等体积生理盐水。应激6h后处死动物,检测各组大鼠胃黏膜一氧化氮(NO)水平、iNOS蛋白和iNOSmRNA的表达,并评估胃黏膜损伤程度。结果水浸鄄束缚应激6h后,大鼠胃黏膜NO水平、iNOS蛋白和iNOSmRNA表达显著增加,胃黏膜病变明显。MT预防组大鼠胃黏膜NO水平、iNOS蛋白和iNOSmRNA表达均显著低于模型组(P<0.01),且溃疡指数(UI)显著下降(P<0.01)。MT高剂量预防组大鼠各检测指标均显著低于MT低剂量预防组(P<0.05),作用呈剂量依赖性。结论MT可预防水浸鄄束缚应激诱导的大鼠胃黏膜损伤,其机制可能与其抑制胃黏膜iNOS过度表达有关。     

聚普瑞锌诱导HSP70保护大鼠胃黏膜损伤

目的探讨聚普瑞锌诱导热休克蛋白70(heat shock protein 70,HSP70)减轻大鼠胃黏膜损伤的作用机制。方法无水乙醇灌胃致大鼠胃黏膜损伤后分别应用聚普瑞锌100 mg/kg、200 mg/kg灌胃及赋形剂灌胃,同时以空白组作对照,检测胃黏膜HSP70蛋白表达。同时检测各实验组大鼠胃黏膜IGF-1含量和SOD活性。结果聚普瑞锌100 mg/kg治疗组治疗3 d时HSP70表达的相对灰度值为278.3%±10.8%;聚普瑞锌200 mg/kg治疗组治疗3 d时HSP70表达的相对灰度值为471.1%±24.7%,与空白组和赋形剂组相比,差异均有统计学意义(P0.01)。各实验组大鼠胃黏膜IGF-1含量和SOD活性差异无统计学意义(P0.05)。结论聚普瑞锌能够诱导损伤后大鼠胃黏膜产生大量HSP70,发挥保护胃黏膜的作用。     

热休克蛋白70对肝硬化门静脉高压性胃病大鼠胃黏膜损伤的保护作用

背景:临床上重度门静脉高压性胃病(PHG)常可引起上消化道致命性大出血。热休克蛋白70(HSP70)是加强胃黏膜防御功能的主要热休克蛋白。目的:探讨HSP70对肝硬化PHG大鼠胃黏膜损伤的保护作用及其机制。方法:以CCl_4制备肝硬化PHG大鼠模型,实验分为正常对照组、PHG组和三组热处理组。以酶联免疫吸附测定(ELISA)检测胃黏膜HSP70和肿瘤坏死因子(TNF)-α水平,并观察胃黏膜病理变化。结果:与正常对照大鼠相比,PHG大鼠胃黏膜HSP70水平明显降低而TNF-α水平明显升高,胃黏膜出现明显病理损伤;热处理组正常大鼠胃黏膜HSP70水平明显升高,TNF-α水平无变化,胃黏膜无明显损伤。与PHG大鼠相比,热处理组PHG大鼠胃黏膜HSP70水平明显升高,TNF-α水平明显降低,胃黏膜损伤明显减轻。结论:HSP70能减轻肝硬化PHG大鼠胃黏膜损伤,其保护作用可能与胃黏膜TNF-α水平降低有关。     

替米沙坦对脑出血急性应激性胃黏膜病变大鼠胃黏膜细胞增殖和凋亡的影响

目的探讨血管紧张素Ⅱ受体拮抗剂替米沙坦对脑出血急性应激性胃黏膜病变大鼠胃黏膜细胞增殖和凋亡的影响。方法健康成年SD大鼠96只,随机分为假手术组、脑出血组、替米沙坦组,每组32只,各组再分为1、2、3和5d4个时间点,每个时间点8只大鼠。制作脑出血大鼠模型,大体观察胃黏膜病变并计算溃疡指数;HE染色光镜下观察胃黏膜组织形态学改变;免疫组织化学法检测胃黏膜增殖细胞核抗原(PCNA)蛋白的表达;TUNEL检测胃黏膜凋亡细胞。结果与假手术组比较,脑出血组大鼠1、2、3和5d胃黏膜溃疡指数明显增大、PCNA表达明显减少、TUNEL凋亡细胞明显增多(P<0.01)。与脑出血组比较,替米沙坦组大鼠1、2、3和5d胃黏膜溃疡指数明显减小、PCNA表达增多、TUNEL凋亡细胞减少(P<0.05)。结论替米沙坦能够减小脑出血急性应激性胃黏膜病变大鼠胃黏膜溃疡指数、增加PCNA表达、减少TUNEL凋亡细胞,减轻应激性胃黏膜病变。     

中药对大鼠血浆及胃粘膜热休克蛋白的影响

采用束缚水浸法造成大鼠急性胃粘膜损伤模型，观察溃疡指数，运用Westerndotblot法检测大鼠血浆及胃组织中热休克蛋白（HSPs）水平的变化。并对目组织的HSPs作免疫组织化学研究、结果表明：热处理组和健脾益气组的溃疡指数极其显著低于模型组（P＜0．01），但血浆及胃组织中的HSPs显著高于模型组（P＜0．05）．溃疡指数与HSPs表达水平呈明显负相关。提示热处理及健脾益气方处理能诱导大鼠提高HSPs的表达，防止胃粘膜损伤，表明HSPs。可能介导胃粘膜防御。     

Tungstic acid reduction of cold-resistant stress-induced ulceration in rats

Sprague-Dawley rats were restrained at 4°C for 2 h (stress). Tungstic acid in a single dose of 0.01, 0.1, 1, 10, 100 or 300 mg/kg (dissolved in distilled water) was administered intragastrically to animals 30 min prior to stress. Stress induced significant gastric mucosal damage, whereas tungstic acid pretreatment dose-dependently reduced lesion formation. Doses of tungstic acid of 1 mg/kg and higher significantly (P < 0.05–0.001) decreased ulcers. The mucosal mast cell counts in rats pretreated with tungstic acid were significantly higher than those of control rats. In motility experiments using oral administration of amberlite pellets, pretreatment with tungstic acid dose-dependently reduced the gastric emptying rate during a 1 h period of stress. Gastric mucosal xanthine oxidase and superoxide dismutase (SOD) activities, after pretreatment with a single dose of tungstic acid, were not altered in stressed animals. It is suggested that tungstic acid effectively antagonizes stress-induced gastric ulcers, possibly by decreasing motility and mass cell degranulation. Xanthine oxidase and SOD activities and mucous content were not changed in the gastric mucosa by the present method of tungstic acid administration.     

Sleep deprivation increase the expression of inducible heat shock protein 70 in rat gastric mucosa

AIM: To investigate if sleep deprivation is able to increase the expression of inducible heat shock protein 70 in gastric mucosa and its possible role in mucosal defense. METHODS: Rats for sleep disruption were placed inside a computerized rotating drum, gastric mucosa was taken from rats with 1, 3 and 7d sleep deprivation. RT-PCR, immunohistochemistry and Western blotting were used to determine the expression of heat shock protein 70. Ethanol (500mL.L(-1), i.g.) was used to induce gastric mucosa damage. RESULTS: RT-PCR, Western blotting and immunostaining confirmed that the sleep deprivation as a stress resulted in significantly greater expression of inducible heat shock protein 70 in gastric mucosa of rats. After the 500mL.L(-1) ethanol challenge, the ulcer area found in the rats with 7d sleep deprivation (19.15 +/- 4.2)mm(2) was significantly lower (P<0.01) than the corresponding control (53.7 +/- 8.1) mm(2). CONCLUSION: Sleep deprivation as a stress, in addition to lowering the gastric mucosal barrier, is able to stimulate the expression of inducible heat shock protein 70 in gastric mucosa of rats, the heat shock protein 70 may play an important role in gastric mucosal protection.     

Expression and immunolocalization of heat shock proteins in the healing of gastric ulcers in rats

BACKGROUND: Heat shock proteins are induced when cells are subjected to noxious stimuli. They afford cytoprotection and increase the resistance of the tissue to damage. However, their roles in the healing of gastric ulcers have not been well established. In this study, the expression and immunolocalization of three heat shock proteins (HSPs); namely inducible HSP70 (iHSP70), HSP47, and HSP32 during ulcer healing were investigated in rats with gastric ulcer. METHODS: Gastric ulcers (kissing ulcers) were induced by luminal application of acetic acid solution. Gastric tissue samples were obtained from the ulcer base, ulcer margin, and non-ulcerated area around the ulcer margin at different time intervals after ulcer induction. The protein levels and distributions of HSPs were analyzed with Western blotting and immunohistochemical methods, respectively. RESULTS: It was found that all HSPs were expressed in normal, non-ulcerated, and gastric ulcer tissues. HSP32 was elevated during inflammation (1-8 days after ulcer induction), while HSP47 expression was exacerbated at the ulcer base and margin during ulcer healing (3-12 days). Decreased expression of iHSP70 was observed at the ulcer base immediately after ulcer induction, but returned to normal level by the end of the healing stage (8-12 days). Inducible HSP70 was found distributed in the gastric glands and injured tissues in the inflamed areas. Wide distribution of HSP47 was detected in granulation tissues and collagen producing cells, while HSP32 was localized in the gastric glands and inflammatory cells. CONCLUSIONS: The findings indicate that iHSP70, HSP47, and HSP32 play different roles during ulcer healing. HSP32 seems to act as an inflammatory defensive factor, and HSP47 as a collagen-specific molecular chaperon contributing significantly to gastric ulcer healing. However, the role of iHSP70 in the ulcer healing process is still undefined.     

酒客乐对酒精性胃黏膜损伤的疗效及其机制的探讨

[目的]探讨中药复方酒客乐对酒精性胃黏膜损伤的防治作用及其机制.[方法]观察各组大鼠实验后胃黏膜的形态学变化,评定胃黏膜损伤指数,用硫代巴比妥酸测定胃黏膜组织丙二醛( MDA)含量,计算胃黏膜凝胶指数,用免疫组化法医学图像分析系统半定量测定胃黏膜组织EGF/EGF-R表达水平.[结果]预防组及治疗组中酒客乐大、小剂量亚组胃黏膜损伤指数和MDA含量均明显低于模型对照亚组(P＜0.01),胃黏液凝胶指数及胃黏膜EGF、EGF-R表达水平均显著高于模型对照组(P＜0.01).[结论]酒客乐对急性酒精性胃黏膜损伤有防治作用,其作用可能与其增强黏膜防御损伤能力有关.     

Preventive effect of hydrotalcite on gastric mucosal injury in rats induced by taurocholate

AIM: To study the preventive effect of hydrotalcite on gastric mucosal injury in rat induced by taurocholate, and to investigate the relationship between the protective mechanism of hydrotalcite and the expression of trefoil factor family 2 (TFF2) mRNA and c-fos protein.METHODS: Forty five male Wistar rats were randomly divided into hydrotalcite group, ranitidine group and control group. Gastric mucosal injury was induced by introgastric acidified taurocholate. OD value of TFF2 mRNA expression in gastric mucous cells was determined by hybridization and computer image analysis system. OD value of c-fos protein expression in gastric mucous cells was measured by immunohistochemistry and computer image analysis system.RESULTS: The gross mucosal injury index in hydrotalcite group was significantly lower than that in ranitidine group and control group (8.60±2.20 vs 16.32±4.27, 29.53±5.39;P＜0.05, P＜0.01). The expression level of TFF2 mRNA in hydrotalcite group was markedly higher than that in ranitidine group and control group (0.56±0.09 vs 0.30±0.05, 0.28±0.03,P＜0.05). The OD value of c-fos protein in hydrotalcite group was higher than that in ranitidine group and control group (0.52±0.07 vs 0.31±0.04, 0.32±0.05, P＜0.05).CONCLUSION: Hydrotalcite can protect gastric mucosal injury in rats induced by taurocholate, which may be related to the increased expression of TFF2 and c-fos protein.     

胃黏膜保护剂的作用及其机制的研究

目的 比较枸橼酸铋钾－1、枸橼酸铋钾－2及蔗糖硫酸酯碱式铝盐（硫糖铝）对胃黏膜的保护作用并研究作用机制。方法 采用乙醇、应激、阿司匹林及盐酸诱发大鼠胃黏膜急性损伤，用50％醋酸接触胃浆膜面产生慢性胃溃疡。枸橼酸铋钾－1、2和硫糖铝的急性损伤药物剂量分别为37.5,40和335mg/kg。给药3d，每天2次；慢性溃疡给药的剂量同急性损伤剂量，但给药11d，每天2次。检查损伤指数及溃疡面积。结果 （1）枸橼酸铋钾－1、枸橼酸铋钾－2和硫糖铝有低抗乙醇、应激、阿司匹林和盐酸诱发的胃黏膜损伤作用，并促进醋酸溃疡的愈合。（2）这种保护黏膜、促进溃疡愈合的作用机制与增加胃黏膜血流量、增加胃黏膜的醌还原酶、谷胱甘肽S－转移酶（GST）和谷胱甘肽还原酶（GR）的 活性及增加碱性成纤维生成因子（bFGF)mRNA和诱导型一氧化氮合酶（iNOS)mRNA的表达有关。结论 保护黏膜药枸橼酸铋钾－1、枸橼酸铋钾－2及硫糖铝有抵抗损伤，促进溃疡愈合的作用，其作用机制是增加胃黏膜血流量，减少氧自由基，增加bFGF及NOS。     

Effect of sucralfate on gastric mucosal blood flow in rats.

Sucralfate possesses site protective and cytoprotective actions and heals ulcers effectively, but its effect on gastric mucosal blood flow is unknown. Using an ex vivo gastric chamber preparation, we studied the effect of sucralfate on gastric mucosal blood flow in rats by laser doppler flowmetry. Under both fasting and fed states, measurements of gastric mucosal blood flow and damage were made in rats after topical application of absolute ethanol alone or after pretreatment with sucralfate. Gastric mucosal damage was assessed by measuring the total area of haemorrhagic mucosal lesions. Ethanol induced gastric mucosal lesions were significantly less with sucralfate pretreatment than without (p less than 0.008). Mucosal blood flow significantly fell after ethanol application (p less than 0.001). The fall was significantly less in fed than in fasted rats (p less than 0.05), and after pretreatment with sucralfate 100 mg or 200 mg than without in both fasted (p less than 0.0008 and 0.00001, respectively) and fed (p less than 0.002 and 0.001, respectively) rats. Graded doses of sucralfate (25-400 mg) resulted in an increase in gastric mucosal blood flow in a dose dependent manner (r = 0.731, p less than 0.001). In conclusion that sucralfate increases gastric mucosal blood flow in rats and lessens the fall in blood flow in rats treated with ethanol, and this action may contribute to its protection against the vascular damage of mucosa by ethanol.