A non-toxic heat shock protein 70 inducer, geranyl-geranyl-acetone, restores the heat shock response in gastric mucosa of protein-malnourished rats

Acute gastric mucosal lesions caused by stress or noxious stimuli are important to consider in the management of critically or chronically ill patients. Protein malnutrition has been implicated as a risk factor for stress ulcer and subsequent complications in those patients. When male Wistar rats fed a 5% or 20% casein diet for 3 weeks were exposed to restraint and water-immersion stress, the low-protein diet significantly increased the ulcer index. The low-protein diet did not change the level of heat shock factor 1 (HSF1) in gastric mucosa but it did attenuate the HSF1 activation after exposure to the stress, resulting in the inhibition of HSP70 mRNA expression and HSP70 induction in gastric mucosa. HSP70 is crucial for the maintenance of cell integrity during pathophysiologic conditions; therefore the impaired HSP70 induction appeared to at least in part aggravate stress ulcer. We also tested whether a non-toxic HSP70 inducer, geranyl-geranyl-acetone (GGA), effectively improved the mucosal integrity by stimulating HSP70 induction under protein malnutrition. Intragastric administration of GGA (200 mg/kg twice a day) to the protein-malnourished rats for up to 1 week failed to stimulate the HSP70 induction. However, the administration of GGA (200 mg/kg twice a day) for 3 weeks restored HSP70 induction and induced higher resistance against stress ulcer as compared with results in vehicle-treated, normally nourished rats. Our results suggest that GGA may have a potential benefit for the prevention of stress ulcer in chronically or critically ill patients with protein malnutrition.     

热休克预处理对严重烫伤大鼠胃黏膜氧自由基的作用

目的:观察热休克预处理对严重烫伤大鼠胃黏膜氧自由基及热休克蛋白(HSP)70表达的影响,探讨氧自由基在大鼠烫伤后急性胃黏膜损伤中的作用及热休克预处理对严重烫伤大鼠胃黏膜的保护作用机制。方法:将96只Wistar大鼠随机分为烫伤组(B组,n=48,其中8只大鼠作为正常对照)及热休克预处理后烫伤组(HB组,n=48,其中8只大鼠作为实验对照),观察各时相点两组大鼠胃黏膜损伤指数(UI)、胃黏膜丙二醛(MDA)及胃黏膜细胞SOD活性变化。应用免疫组化染色分析胃黏膜细胞中HSP 70表达变化。结果:大鼠严重烫伤后胃黏膜细胞SOD大量消耗,MDA显著增加,胃黏膜损害明显;热休克预处理能显著减轻大鼠严重烫伤后急性胃黏膜损害。HB组较B组大鼠胃黏膜HSP 70表达水平显著升高(P<0.05),热休克预处理能显著降低胃黏膜细胞SOD的消耗,减少MDA的产生。胃黏膜损伤指数(UI)与MDA呈显著正相关(r=0.695,P<0.01),与HSP 70呈显著负相关(r=-0.794,P<0.01);胃黏膜SOD与MDA呈显著负相关(r=-0.823,P<0.01),而与HSP 70呈显著正相关(r=0.527,P<0.05)。结论:严重烫伤大鼠胃黏膜存在氧自由基损伤;热休克预处理可显著减轻烫伤大鼠胃黏膜氧自由基损伤,保护机制与HSP 70保护抗氧化酶SOD活性密切相关。     

Glutathione depletion impairs transcriptional activation of heat shock genes in primary cultures of guinea pig gastric mucosal cells.

When primary cultures of guinea pig gastric mucosal cells were exposed to heat (43 degree C), ethanol, hydrogen peroxide (H2O2), or diamide, heat shock proteins (HSP90, HSP70, HSP60, and HSC73) were rapidly synthesized. The extent of each HSP induction varied with the type of stress. Ethanol, H2O2, and diamide increased the syntheses of several other undefined proteins besides the HSPs. However, none of these proteins were induced by exposure to heat or the reagents, when intracellular glutathione was depleted to <10% of the control level by pretreatment with DL-buthionine-[S,R]-sulfoximine. Gel mobility shift assay using a synthetic oligonucleotide coding HSP70 heat shock element showed that glutathione depletion inhibited the heat- and the reagent-initiated activation of the heat shock factor 1 (HSF1) and did not promote the expression of HSP70 mRNA. Immunoblot analysis with antiserum against HSF1 demonstrated that the steady-state level of HSF1 was not changed in glutathione-depleted cells, but glutathione depletion inhibited the nuclear translocation of HSF1 after exposure to heat stress. These results suggest that intracellular glutathione may support early and important biochemical events in the acquisition by gastric mucosal cells of an adaptive response to irritants.     

Long-term enhanced expression of heat shock proteins and decelerated apoptosis in polymorphonuclear leukocytes from major burn patients

Heat shock proteins (HSPs), as molecular chaperones, have been reported to protect cells against a variety of environmental stresses. The objective of this study was to clarify the serial changes in expression of HSPs, oxidative activity, and apoptosis in polymorphonuclear leukocytes (PMNLs) from burn patients. Eight patients with severe burns (mean burn index 24.0 +/- 6.1) were included. Blood samples were serially obtained at five time points: days 0 to 1, days 2 to 7, days 8 to 14, days 15 to 21, and days 22 to 28. We measured expressions of HSP27, HSP60, HSP70, and HSP90 in permeabilized PMNLs by flow cytometry with the use of a monoclonal antibody against each HSP. The oxidative activity and apoptosis in PMNLs were also measured by flow cytometry. During all five time periods, expressions of HSP27, HSP60, and HSP70 in PMNLs from burn patients were significantly greater than those in PMNLs from healthy volunteers. The expression of HSP90 in PMNLs of burn patients increased between days 2 and 21. Oxidative activity in their PMNLs was significantly enhanced between days 2 and 28, and PMNL apoptosis was markedly inhibited for as long as 4 weeks after thermal injury. In conclusion, major burn causes long-term, enhanced expression of HSPs in PMNLs along with increased oxidative activity and decelerated apoptosis. The enhanced expression of HSPs may regulate the oxidative stress response and life-span of PMNLs in burn patients.     

慢性胃炎病变黏膜组织HSP70的表达与幽门螺杆菌感染的相关性研究

目的探讨导致慢性胃炎的主要病因幽门螺杆菌（Hp）感染与病变黏膜组织中热休克蛋白70（HSP70）表达的相关性,旨在为临床判定慢性胃炎的严重程度、发展趋势和治疗前景提供依据。方法收集慢性胃炎胃黏膜胃镜活检标本71例,所有标本均经病理证实,其中浅表性胃炎38例,萎缩性胃炎33例。经吉姆萨染色结合临床^14C尿素呼气试验测定Hp,把所有病例分为Hp阳性组和Hp阴性组;用免疫组织化学技术测定黏膜组织中HSP70,计算两组黏膜组织HSP70表达阳性率,经统计学方法比较其差异显著性。结果不论浅表性胃炎还是萎缩性胃炎,Hp阳性组黏膜组织中HSP70表达阳性率（分别为61．5％和76．0％）显著高于Hp阴性组黏膜组织HSP70表达阳性率（分别为25．0％和37．5％）,差异具有显著性（P〈0．05）。结论HSPT0在各型慢性胃炎黏膜组织均有表达,Hp感染使其表达量明显增强。测定HSP70可反映Hp感染的严重程度和疾病的发展趋势及治疗前景。     

局部微波热疗对热休克蛋白表达的影响

目的探讨骨肉瘤术中热疗对热休克蛋白表达的影响。方法对61例骨肉瘤组织进行免疫组化染色,观察热休克蛋白HSP-60、HSP-70及GP-94的表达。结果骨肉瘤组织中GP-94表达最高,阳性率为100%,其次为HSP-60,阳性率为94.5%,HSP-70弱表达,阳性率41.8%。热疗后HSP均不同程度增多,以HSP-70较明显,阳性率上升到72%。体外骨肉瘤细胞株加热后热休克蛋白也明显增多。结论局部微波热疗后,3种热休克蛋白在骨肉瘤组织均有表达。     

严重烧伤早期肠黏膜组织热休克蛋白70的表达规律

目的探讨大鼠烧伤后早期肠黏膜组织热休克蛋白70(HSP70)的表达变化规律及其意义。方法采用大鼠烫伤模型,通过逆转录-聚合酶链反应(RT-PCR)、蛋白质免疫印迹(Westernblot)及免疫组化等方法,检测伤后3、6、12、24和48h不同时间点肠黏膜组织内HSP70及热休克因子1(HSF1)的表达分布情况。结果烫伤后3h肠黏膜组织内HSP70mRNA及蛋白表达均显著增加,分别在伤后6h和12h达高峰,伤后48h仍高于正常对照组(P均<0.01);伤后3h大鼠肠黏膜组织HSF1出现一过性降低,伤后6h其表达显著高于正常对照组,并呈逐渐增加的趋势直至持续到伤后48h(P均<0.01)。结论严重烧伤早期肠黏膜组织HSP70及HSF1表达均显著增加,提示严重烧伤早期即可引起肠黏膜组织细胞的应激反应,可能与细胞的自我保护机制启动有关。     

Induction of cyclooxygenase-2 in rat gastric mucosa by rebamipide, a mucoprotective agent

Recent studies indicate an expression of mitogen-inducible cyclooxygenase (COX-2) in gastric mucosa. Rebamipide, a mucoprotective agent enhances prostaglandin (PG) synthesis. The present study was designed to clarify the mechanism for rebamipide-induced mucosal protection. Male Sprague-Dawley rats were administered 5, 15, or 50 mg/kg/day rebamipide for 14 days. The expression of constitutive cyclooxygenase (COX-1) and COX-2 in gastric mucosa was determined using Western blot analysis. Another series of rats was used to examine 1) the levels of PGE(2) in stomach with and without pretreatment with a COX-2 inhibitor; 2) the protective action of rebamipide against gastric damage caused by 0.6 N HCl; and 3) the effects of a COX-2 inhibitor on rebamipide-induced gastric mucosal protection. COX-2 expression was enhanced, whereas COX-1 expression did not change significantly in the gastric mucosa of rats after treatment with rebamipide. The gastric mucosal PGE(2) was higher in the rebamipide groups than in the vehicle-treated group. Rebamipide also suppressed gastric damage induced by HCl in a dose-dependent manner. A COX-2 inhibitor blocked the rebamipide-induced increase in mucosal PGE(2), and mucosal protection induced by rebamipide. The results indicate that rebamipide induces COX-2 expression, increases PGE(2) levels, and enhances gastric mucosal defense in a COX-2-dependent manner. Thus, COX-2 has an important role in the effects of rebamipide on gastric mucosal protection.     

原发免疫性血小板减少症患者外周血单个核细胞热休克蛋白90的表达及与激素疗效相关性分析

目的 探讨原发免疫性血小板减少症(ITP)患者糖皮质激素受体分子伴侣--热休克蛋白90(HSP90)表达特点及与激素疗效、部分临床指标的相关性.方法 采用实时荧光定量PCR方法检测44例初发ITP患者外周血单个核细胞(PBMC)的HSP90 mRNA,同时检测32例正常人作为对照.将ITP患者按糖皮质激素(GC)治疗效应分为GC敏感组和GC抵抗组,再按年龄、性别、病程和病情进行分组比较,同时分析患者HSP90 mRNA与血小板数、骨髓巨核细胞数及血小板抗体IgG的相关性.结果 44例ITP患者外周血PBMC的HSP90 mRNA中位数为0.90(0.48～2.52),32例正常人为1.40(0.82～2.65),正常人较ITP患者HSP90 mRNA有升高趋势,但两组无统计学差异(P>0.05).成人急性ITP患者HSP90 mRNA表达显著高于慢性患者(P<0.05).GC敏感组HSP90 mRNA表达中位数高于抵抗组,但两组无统计学差异(P>0.05).再按性别、年龄和病情分组比较,可见年龄≤60岁较年龄>60岁患者,轻型较重型患者,HSP90 mRNA均有升高趋势,但亦无统计学差异(P>0.05).ITP患者HSP90 mRNA水平与血小板数、骨髓巨核细胞数及血小板抗体IgG无明显相关性.结论 HSP90 mRNA在急性ITP患者显著高于慢性患者,显示与病程密切相关,结合其在GC敏感组较抵抗组表达升高的趋势,推测其在ITP中表达下调与GC抵抗有关联.     

银黄液对大鼠膀胱黏膜急性损伤保护作用的实验研究

目的探讨银黄液对大鼠膀胱黏膜急性损伤的保护作用及黏膜损伤后修复的影响。方法将32只SPF级成年雌性SD大鼠随机分为A、B、C、D共4组,每组8只,A组为正常对照组,B组为模型对照组,C组为治疗组,D组为预防治疗组。膀胱内灌注盐酸制作膀胱黏膜损伤的动物模型,并在建模前或建模后膀胱内灌注银黄液。通过HE染色、组织学损伤评分和膀胱组织中HSP70的表达评估各组炎症严重程度,并分析与黏膜受损程度的关系。结果光镜下病理改变,B组有大量炎性细胞浸润、毛细血管明显扩张,上皮细胞坏死。C组少量的炎性细胞浸润、毛细血管扩张。D组少量炎性细胞浸润,无或仅有少量炎性细胞浸润;组织学损伤评分,A组组织学损伤轻微,B组评分明显高于C、D组(P<0.01),C组评分高于D组(P<0.05);HSP70的表达,A组HSP70表达程度明显低于B、C、D组(P<0.01),B组表达明显高于C、D组(P<0.01),C组表达高于D组(P<0.05)。结论银黄液可以提高膀胱黏膜抗急性化学性损伤作用以及促进损伤后的膀胱黏膜修复。     

热休克蛋白90α、70、27mRNA在急性白血病细胞中表达的研究

运用RNA分子杂交的方法,观察了热休克蛋白(heat shock protein,HSP)90α、70、27在22例白血病病人细胞,正常血细胞及K562红白血病细胞系中的表达。结果表明:16例白血病病人中,4例急性淋巴细胞白血病(ALL),6例急性非淋巴白血病(ANLL)、1例慢性粒细胞白血病急变期(慢粒急变)和2例骨髓增生异常综合征(MDS)血细胞呈现HSP27高水平表达,较正常血细胞显著增多,ALL(5例)与ANLL(7例)白血病细胞HSP27表达水平无明显改变。检测了7例白血病细胞HSP70的表达水平,除1例ALL及1例MDS明显升高外,其余5例(包括1例ALL,3例ANLL和1例慢粒急变)显著低于正常血细胞。17例白血病病人细胞(包括9例ANLL、5例ALL、2例慢粒急变和1例MDS)HSP90α表达水平均升高,明显高于正常。结果提示:白血病细胞HSP90α表达水平的升高可能与白血病细胞活跃异常增殖有关,而HSP27基因的高表达可能不是某种急性白血病的特殊标志。     

热休克蛋白与大肠癌发生、发展及生物学行为的关系

目的了解不同类型热休克蛋白(HSP)在大肠癌组织中的表达,并探讨其与大肠癌的发生、发展及生物学行为的关系。方法收集大肠癌患者标本存档蜡块48例,32例选自中国医科大学附属第二临床医院内窥镜中心,应用肠镜取材的病例标本,16例选自本院外科大肠癌手术后标本,48例标本分为两组,一组为大肠癌组织取材标本;另一组为同一大肠癌患者距癌组织10～15cm正常癌旁黏膜组织取材。应用免疫组化SABC法观察40例大肠癌组织和癌旁正常组织中HSP60、70、90α的表达,并比较期间是否存在差异性。结果大肠癌组织和癌旁正常组织粘膜中HSP60、70、90α的阳性表达率分别为54%、60%、79%和21%、17%、21%.3种HSP在癌组织与癌旁正常组织中表达差异均有显著性意义(χ2=13.653,21.333,28.800,P<0.01)。结论3种HSP可在大肠癌中呈高表达,各类型HSP的表达与大肠癌的分化程度及淋巴节转移无关,但HSP在直肠癌中的过量表达提示预后不良,可做为直肠癌预后判定监测标记。     

JAK2/STAT3信号通路在应激性溃疡大鼠胃黏膜炎症反应中的作用研究

目的：探讨Janus激酶2（JAK2）/信号转导与转录激活子3（STAT3）信号通路在应激性溃疡（SU）的胃黏膜炎症反应过程中的作用。方法：选用雄性清洁级SD大鼠96只,随机分为4组,分别为：正常对照组（NC组）、应激性溃疡组（SU组）、抑制剂组（AG490组）、二甲基亚砜组（DMSO组）。建立水浸束缚SU大鼠模型。4组大鼠分别于实验开始后2h、4h、8h、16h各取6只,测定胃黏膜血流量（GMBF）,计算溃疡指数（UI）。观察胃黏膜组织学变化,测定TNF-α、IL-1β、IL-6以及JAK2、p-JAK2、STAT3、p-STAT3的表达量。结果：SU组GMBF明显低于NC组,而UI明显高于NC组（P〈0.01）;AG490组GMBF明显高于SU组,而UI明显低于SU组（P〈0.01）。通过造模前给予抑制剂AG490,胃黏膜病理学变化明显改善。SU组TNF-a、IL-1β、IL-6以及p-JAK2、p-STAT 3表达量明显高于NC组（P〈0.01）,而AG490组较SU组显著降低（P〈0.01）。结论：JAK2/STAT 3信号通路参与了SU大鼠胃黏膜炎症反应过程,使用JAK2特异性抑制剂AG490可以减轻SU大鼠胃黏膜炎症反应。     

Heat shock proteins and ventilator-induced lung injury

In this review, we discuss the heat shock response, a specific example of gene expression that has been studied over the past 25 years, and its relevance to acute lung injury and other critical conditions. The heat shock response has been observed in virtually all organisms and involves the rapid induction of a set of highly conserved genes that encode heat shock proteins (HSPs). The HSP70 family represents the most prominent eukaryotic group of HSPs. It has been suggested that members of the HSP70 family act in the protection of cellular damage by binding to denatured or abnormal proteins after heat shock, thereby preventing protein aggregation. The capacity of HSPs to subserve cytoprotection has produced considerable interest from the perspective of elucidating the pathophysiology of organ damage and dysfunction. Several studies support the hypothesis that HSPs are cytoprotective In addition, recent investigations have demonstrated that HSP70 is released into the systemic circulation and is involved in the activation of innate immunity.     

T cells reactive to an inducible heat shock protein induce disease in toxin-induced interstitial nephritis

T cells reactive against immunodominant regions of inducible heat shock proteins (HSPs) have been identified in the chronic inflammatory lesions of several experimental autoimmune diseases. Since HSPs are known to be induced by a number of renal tubular epithelial cell toxins associated with chronic interstitial nephritis, we investigated the relevance of HSP expression and T cell reactivity to HSP70 in a model of progressive inflammatory interstitial nephritis. Chronic administration of cadmium chloride (CdCl2) to SJL/J mice induces HSP70 expression in renal tubular cells 4-5 wk before the development of interstitial mononuclear cell infiltrates. CdCl2 also induces HSP70 expression in cultured tubular epithelial cells from SJL/J mice. CD4+, TCR-alpha/beta+ T cell lines specific for an immunodominant HSP peptide are cytotoxic to heat stressed or CdCl2-treated renal tubular cells. Such HSP-reactive T cells mediate an inflammatory interstitial nephritis after adoptive transfer to CdCl2-treated mice at a time when immunoreactive HSP70 is detectable in the kidneys, but before the development of interstitial mononuclear cell infiltrates. T cells isolated from the nephritic kidneys of mice treated with CdCl2 for 13 wk are also cytotoxic to heat shocked or cadmium-treated tubular cells. These kidney-derived T cells additionally induced interstitial nephritis after passive transfer, indicating their pathogenic significance. Our studies strongly support a role for HSP-reactive T cells in CdCl2-induced interstitial nephritis and suggest that the induction of HSPs in the kidney by a multitude of "non-immune" events may initiate or facilitate inflammatory damage by HSP-reactive lymphocytes.     

不同病因导致的应激性胃黏膜损伤中环氧化酶-2的改变

目的探讨不同病因导致的应激性胃黏膜损伤时胃黏膜环氧化酶（cyclooxygenase,COX）-2表达强度的变化及二者的关系。方法通过建立急性甲胺磷中毒及急性心肌梗死动物模型,采用胃黏膜溃疡指数评定是否发生胃黏膜损伤,采用免疫组化方法测定胃黏膜COX-2的表达强度变化。结果①成功建立大鼠急性甲胺磷中毒及急性心肌梗死动物模型;②在急性甲胺磷中毒及急性心肌梗死这两种应激状态下胃黏膜发生了损伤;③不同病因所致应激性胃黏膜损伤时胃黏膜COX-2表达增加。结论临床危重疾病可产生应激状态胃黏膜损伤,胃黏膜溃疡指数增加。不同病因所致的应激性胃黏膜损伤时胃黏膜COX-2表达增加,可能为一种保护机制。     

Synthesis of stress proteins in rat cardiac myocytes 2-4 days after imposition of hemodynamic overload.

Isolated adult myocytes incubated with [35S]methionine were used to study the expression of proteins in the rat heart during the first 2 wk after either pressure or volume overload. In both models an early (2-4 d) and transient expression of three major stress proteins (heat shock protein [HSP] HSP 70, HSP 68, and HSP 58) was observed together with an increased synthesis of putative ribosomal proteins. Only traces of 35S-labeled HSPs were detected in controls and sham-operated animals. The three stress proteins were identified by their migration in two-dimensional gels, by comigration with HSPs, which had been induced in myocytes by incubation at 41 degrees C and immunoblot analysis using antisera directed against the 70-kD protein. Immunohistochemical staining of HSP 70 in rod-shaped myocytes and detection by immunoblot showed that HSP 70 was equally present and distributed in both sham-operated and overloaded hearts, and provided no evidence for a subpopulation of myocytes acutely involved in the increased expression of HSP 70. It is suggested that the transient expression of HSPs that occurs during the early adaptation of the myocardial cells to overload could confer some degree of protection to the actively growing myocytes.     

胃癌组织中Ezrin表达及其意义

目的探讨埃兹蛋白在胃癌组织中的表达及其意义。方法分别选取胃癌组织标本40例、不典型增生胃黏膜组织标本20例及正常胃黏膜组织标本10例,检测分析其Ezrin mRNA及蛋白的表达及意义,检测方法采用原位杂交及免疫组化法。结果 EzrinmRNA和蛋白阳性表达率,胃癌组织<不典型增生胃黏膜<正常胃黏膜,且三者差异有统计学意义(P<0.01);在不同浸润深度、肿瘤大小及有无淋巴结转移组内Ezrin mRNA和蛋白阳性表达率有明显的差异(P<0.05),但在年龄、性别和脉管侵犯组内没有明显的差异(P>0.05);Ezrin mRNA正比于蛋白表达率(rs=0.99,P<0.01)。结论胃癌产生、发展及转移在很大程度上会导致Ezrin表达下降。     

Zinc Supplementation with Polaprezinc Protects Mouse Hepatocytes against Acetaminophen-Induced Toxicity via Induction of Heat Shock Protein 70

Polaprezinc, a chelate compound consisting of zinc and l-carnosine, is clinically used as a medicine for gastric ulcers. It has been shown that induction of heat shock protein (HSP) is involved in protective effects of polaprezinc against gastric mucosal injury. In the present study, we investigated whether polaprezinc and its components could induce HSP70 and prevent acetaminophen (APAP) toxicity in mouse primary cultured hepatocytes. Hepatocytes were treated with polaprezinc, zinc sulfate or l-carnosine at the concentration of 100 µM for 9 h, and then exposed to 10 mM APAP. Polaprezinc or zinc sulfate increased cellular HSP70 expression. However, l-carnosine had no influence on it. Pretreatment of the cells with polaprezinc or zinc sulfate significantly suppressed cell death as well as cellular lipid peroxidation after APAP treatment. In contrast, pretreatment with polaprezinc did not affect decrease in intracellular glutathione after APAP. Furthermore, treatment with KNK437, an HSP inhibitor, attenuated increase in HSP70 expression induced by polaprezinc, and abolished protective effect of polaprezinc on cell death after APAP. These results suggested that polaprezinc, in particular its zinc component, induces HSP70 expression in mouse primary cultured hepatocytes, and inhibits lipid peroxidation after APAP treatment, resulting in protection against APAP toxicity.     

Importance of gap junction in gastric mucosal restitution from acid-induced injury

Evidence is accumulating that gap junctional intercellular communication (GJIC) plays an important role in the gastric mucosal defense system. This study was conducted to determine whether GJIC mediates a restitution process in gastric mucosa. Male Sprague-Dawley rats were fasted and anesthetized. Gastric injury was induced by luminal perfusion with 0.2N HCl for 10 minutes. Mucosal integrity was continuously monitored by measuring the clearance of chromium 51-labeled ethylenediaminetetraacetic acid, which was used for analysis of recovery from the injury. Perfusion with 0.25% octanol (OCT; inhibitor of GJIC) was started after acid injury to assess its effect on restitution. The effect of irsogladine (IG; activator of GJIC) was also tested. Gastric mucosal GJIC was immunohistochemically evaluated with monoclonal antibody gap junction protein (connexin 32). Recovery from acid-induced mucosal injury occurred rapidly when acid perfusion was discontinued (within about 60 minutes). OCT, which didn't cause any injury to normal gastric mucosa, significantly inhibited the restitution. IG reversed this inhibition in a dose-dependent manner. In an immunohistochemical study, OCT-induced damage of gap junction was demonstrated, but not after IG pre-treatment. These findings suggest that GJIC may play a critical role in restitution in rat gastric mucosa and that gap junction function may be one of the important factors for the mucosal defense system.