Interventional effect of Ginkgo biloba extract on the progression of gastric precancerous lesions in rats

OBJECTIVE: To investigate the effect of Ginkgo biloba extract on gastric precancerous lesions in rats. METHODS: 80 4‐week‐old Wistar rats were randomly divided into four groups: a control group, a model group, a low and a high dose Ginkgo biloba extract intervention group; 20 in each group. Gastric precancerous lesions were induced by giving them 100 mg/L N‐methyl‐N′‐nitro‐N‐nitrosoguanidine (MNNG) solution to drink ad libitum for 20 weeks. In addition to the MNNG, the intervention groups were lavaged with Ginkgo biloba extract (0.5 mg/kg/d in the low dose group, 1.5 mg/kg/d in the high dose group) for 20 weeks. Starting from week 21 all the rats were fed with normal rat chow and tap water. At the end of week 30 the rats were killed. The histopathological changes of their gastric mucosa, ISA, NGI, the serum and gastric mucosal SOD/MDA and the expressions of oncogenes were studied. RESULTS: The incidence of mild to severe intestinal metaplasia and dysplasia were significantly lower in the intervention groups than those in the model group (P < 0.01). The ISA and NGI in the intervention groups were significantly lower than those in the model group (P < 0.01). In the intervention groups the activity of SOD was increased and the concentration of MDA was decreased (P < 0.01). Expressions of Bcl‐2, c‐myc and FasL decreased in the intevention groups, whereas the expression of Fas increased. When compared with the model group, the differences were statistically significant (P < 0.01, P < 0.05, respectively). CONCLUSION: Ginkgo biloba extract can increase anti‐oxidative activity and inhibit the progression of gastric precancerous lesions via the regulation of cell proliferation and apoptosis.     

Influence of NG‐nitro‐L‐arginine methyl ester and L‐arginine on gastric mucosal tolerant cytoprotection under stress

OBJECTIVE : To determine the role of endogenous nitric oxide (NO) in gastric mucosal tolerant cytoprotection under stress and its possible mechanism. METHODS : Sprague–Dawley rats were exposed to repeated water immersion and restraint stress (WRS), during which N^G‐nitro‐L ‐arginine methyl ester (L ‐NAME), a non‐selective NO synthase inhibitor, and L ‐arginine (L ‐Arg), a substrate for NO synthesis, were administered to inhibit or promote the synthesis of endogenous NO, respectively. Gastric mucosal blood flow (GMBF) was measured with an LDF‐3 Flowmeter (Electronic Instrument Factory of Nankai University, Tianjin, China), the NO level in the gastric mucosa was monitored by the Griess reaction and gastric mucosal lesions were evaluated using the ulcer index (UI). The relationships between changes in GMBF, UI and NO content in the gastric mucosa were analyzed by linear correlation analysis. RESULTS : Repeated WRS induced gastric mucosal tolerant cytoprotection and this was accompanied by increased GMBF and NO levels in the gastric mucosa. Inhibition of endogenous NO synthesis by L ‐NAME worsened mucosal lesions induced by single WRS and, after repeated WRS, the adaptive incremence in GMBF was abolished and the NO content in the gastric mucosa was significantly reduced. In contrast, enhancement of endogenous NO synthesis by L ‐Arg attenuated mucosal erosions caused by single WRS. After repeated WRS, GMBF and the NO content in the mucosa increased gradually. Mucosal lesions were negligible after rats were exposed to the fourth WRS. CONCLUSIONS : During the tolerant cytoprotection, GMBF, UI and the NO content showed regular changes and there were good relationships between them. L ‐NAME and L ‐Arg changed the levels of endogenous NO, which, accordingly, affected GMBF and the gastric tolerance. By regulating GMBF, endogenous NO may play an important role in the gastric mucosal tolerant cytoprotection under stress. Inhibition of the synthesis of NO delayed the induction of tolerant cytoprotection, whereas increased NO synthesis promoted cytoprotection.     

应激状态下大鼠胃黏膜组织中内皮素-1A受体mRNA的表达及其意义

应激性溃疡(SU)是危重疾病的常见严重并发症,其发生机制尚不清楚。研究表明内源性缩血管因子内皮素(ET)-1与SU密切相关,而关于其受体表达在SU发生中作用的研究尚少。目的:探讨ET-1A受体(ETAR)mRNA表达在SU发生中的作用和意义。方法:以冷束缚应激(CRS)制备大鼠胃溃疡模型,应激前和应激1 h、3 h、6 h、9 h、12 h后分别采用放射免疫测定、逆转录聚合酶链反应(RT-PCR)和斑点杂交等方法,动态检测血浆和胃黏膜组织中的ET-1和胃黏膜组织中的ETAR mRNA水平,同时检测胃黏膜血流量(GMBF)和溃疡指数(UI)等指标的变化情况。结果:与正常对照组相比,各应激组大鼠血浆和胃黏膜组织中的ET-1水平均显著升高(P<0.05),GMBF显著下降(P<0.01),UI显著增加(P<0.01);胃黏膜组织中的ET-1水平与UI呈显著正相关(r=0.98,P<0.01),与GMBF呈显著负相关(r=-0.89,P<0.05),而血浆ET-1水平与GMBF、UI相关性不显著(r=-0.61,0.43,P>0.05)。GMBF与UI呈显著负相关(r=-0.98,P<0.01)。RT-PCR和斑点杂交显示各应激组大鼠胃黏膜组织中ETAR mRNA的表达水平较正常对照组显著升高(P<0.01),并与胃黏膜组织中的ET-1水平和UI呈显著正相关(r=0.93,0.95,P<0.01)。结论:在CRS诱发大鼠急性胃黏膜损伤的过程中,胃黏膜组织可显著增加ET-1的合成分泌和ETAR mRNA的     

参芪消痞汤对慢性萎缩性胃炎癌前期病变胃黏膜修复作用和血管生成机制及血清p53、MDA、GSH-Px的相关影响

目的:观察参芪消痞汤对慢性萎缩性胃炎(CAG)癌前期病变大鼠胃黏膜表皮生长因子(EGF)、表皮生长因子受体(EGFR)表达水平与缺氧诱导因子(HIF-1α)、血管内皮生长因子(VEGF)及血清p53、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-Px)的相关影响.方法:选择60只健康SD雄性大鼠喂养1周后,根据体重随机...     

表皮生长因子对SD大鼠萎缩性胃炎的作用

目的探讨表皮生长因子（EGF）对大鼠慢性萎缩性胃炎(CAG)胃黏膜病变的作用。方法将已经建立的SD大鼠CAG模型随机分成治疗组和对照组,治疗组给予EGF10μg/kg皮下注射,每日1次;对照组给予等容生理盐水皮下注射,每日1次,刺激12周后取出全胃,观察各组大鼠胃黏膜病理变化。结果治疗组大鼠胃黏膜炎性细胞浸润程度较对照组明显减轻（P<0.01）;两组大鼠胃黏膜腺体层厚度分别为(215.0±20.7)μm和(139.2±13.8)μm（P<0.01）,胃黏膜腺体层厚度/黏膜肌层厚度分别为2.70±0.34和1.27±0.27（P<0.01）,单位长度内胃黏膜腺体数目分别为26.20±1.27和19.90±1.78（P<0.01）;治疗组胃黏膜腺体增殖细胞核抗原(PCNA)表达阳性的宽度(77.70±4.16)μm较对照组(54.40±4.54)μm明显增加（P<0.01）。治疗组大鼠胃黏膜腺体排列规则,未发现有恶性增殖现象。结论EGF对SD大鼠CAG模型的胃黏膜萎缩有逆转治疗作用。EGF促进大鼠胃黏膜细胞PCNA阳性表达是其对大鼠CAG损伤的保护性增殖作用。     

健脾理气颗粒对大鼠胃溃疡作用的研究

目的：研究健脾理气颗粒对大鼠胃溃疡及胃粘膜损伤的作用。方法：采用水浸应激致胃溃疡及口服乙醇致胃粘膜损伤法制模，再用健脾理气颗粒3个剂量组进行药效评价，并设对照组进行比较。结果：健脾理气颗粒3个剂量组对大鼠应激性胃溃疡的形成有明显的抑制作用（P＜0.05-0.01)，对口服乙醇致胃粘膜损伤也有保护作用，尤以10g/kg、20g/kg组为明显（P＜0.05-0.01)。结论：健脾理气颗粒具有明显地抑制大鼠胃溃疡及保护胃粘膜损伤作用。     

自由基在实验性胃癌及癌前病变发生中的作用

目的探讨自由基在胃癌及其癌前病变发生中的作用．方法将１００只Ｗｉｓｔａｒ大鼠分为２组，实验组（７０只），给予１００ｍｇ／Ｌ甲基硝基亚硝基胍（ＭＮＮＧ）水溶液自由饮用３０ｗｋ，对照组（３０只）饮用自来水．选５个时相点，动态观察ＭＮＮＧ诱发实验性胃癌及其癌前病变过程中大鼠体内丙二醛（ＭＤＡ）、脂质过氧化物（ＬＰＯ）、谷胱甘肽过氧化物酶（ＧＳＨＰＸ）及超氧化物歧化酶（ＳＯＤ）等的变化情况．结果在实验组，ＭＤＡ平均含量在５２ｗｋ非常显著地大于０ｗｋ（Ｐ＜００１），并显著地大于１６ｗｋ以前（Ｐ＜００５）．胃癌组织ＭＤＡ含量显著高于胃癌癌前病变组织（Ｐ＜００５）．癌组织ＬＰＯ的含量显著高于癌前病变组织（Ｐ＜００５）．实验组，总ＳＯＤ和ＣｕＺｎＳＯＤ活性在５２ｗｋ明显低于１６ｗｋ之前（分别为Ｐ＜００５和Ｐ＜００１）．癌组织ＣｕＺｎＳＯＤ含量非常显著地小于正常胃粘膜（Ｐ＜００１），亦明显低于胃粘膜异型增生和肠上皮化生（Ｐ＜００５）．在３０ｗｋ和５２ｗｋＧＳＨＰＸ活性显著低于１６ｗｋ以前．结论自由基在实验性胃癌及其癌前病变发生中具有一定作用，自由基清除剂可能对胃癌的综合防治具有积极意义     

热水诱导慢性萎缩性胃炎大鼠胃黏膜组织p53和增殖细胞核抗原蛋白的表达

背景：慢性萎缩性胃炎（CAG）属胃癌癌前状态,高热饮食是CAG发生的危险因素之一。目的：观察热水诱导CAG大鼠胃黏膜组织中p53和增殖细胞核抗原（PCNA）蛋白的表达,探讨长期高热饮食与CAG和胃癌的可能关系。方法：以55℃蒸馏水灌胃建立大鼠CAG模型。分别于灌胃第8、12、24、32和65周取腺胃组织,光学显微镜下观察胃黏膜组织学改变;采用免疫荧光技术标记p53和PCNA蛋白,行激光扫描共聚焦显微镜观察。结果：热水灌胃组第24周时胃黏膜开始出现萎缩改变。温水灌胃组各时间点胃黏膜均未见p53和PCNA蛋白表达。热水灌胃组第24周时胃黏膜细胞核中即可见p53蛋白绿色荧光和PCNA蛋白红色荧光表达,第32周和65周时表达更为明显。免疫荧光双标记时可见两种蛋白共表达。结论：热水灌胃可致大鼠CAG并引起胃黏膜癌相关基因p53和PCNA蛋白表达增强,可能与胃癌的发生有关。     

血管活性肠肽参与电针对大鼠胃粘膜损伤的保护作用

目的：探讨血管活性肠肽(VIP)参与电针对胃粘膜损伤大鼠保护作用的机制。方法：采用束缚冷应激胃粘膜损伤大鼠模型，通过放射免疫测定法和中枢迷走背核复合体(DVC)微量注射，观察电针对各组外周血、胃粘膜和脑组织的VIP含量的变化，胃粘膜血流量(GMBF)、损伤指数(LI)和跨壁电位差(PD)的影响。结果：电针模型组外周血、胃粘膜和脑组织VIP含量均增加，GMBF、PD也明显增加，LI下降；中枢DVC微量注射VIP后，外周血和胃粘膜中VIP含量增加。结论：VIP作为信号分子，通过神经内分泌免疫网络系统对胃粘膜损伤具有整体调控作用。     

电针足阳明经穴对胃粘膜损伤大鼠胃粘膜血流量及生长抑素的影响

目的 :观察电针足阳明经“四白”、“天枢”、“足三里”穴对胃粘膜损伤大鼠胃窦和延髓内生长抑素(SS)含量的影响及与胃粘膜损伤、胃粘膜血流量的关系 ,以探讨经脉 -脏腑相关的物质基础。方法 :健康 SD大鼠 6 0只 ,随机分为正常对照组 (对照组 ) ,模型组 ,针刺四白组、天枢组及非穴点组共 6组 ,以乙醇灌胃造成胃粘膜损伤大鼠模型 ,观察电针大鼠足三里、天枢、四白穴对胃粘膜血流量 (氢气清除法 )的影响 ,用放免分析法检测大鼠胃窦及延髓 SS含量。结果 :胃粘膜血流量在胃粘膜损伤后明显降低 ,针刺四白、天枢、足三里及非穴点后 ,均有不同程度升高 ,尤以足三里和四白组升高明显 (P<0 .0 1) ;胃窦及延髓 SS模型组较对照组升高 (P<0 .0 5 ,<0 .0 1) ,而针刺四白、足三里组升高不明显 (P>0 .0 5 )。结论 :胃窦、延髓 SS含量变化与胃粘膜血流量的改变有一定关系 ,电针足阳明经四白、足三里穴可能通过对胃窦及延髓 SS含量的改变来影响胃粘膜血流量 ,促进胃粘膜损伤的修复。     

莪蚕健胃方治疗大鼠胃癌前病变作用机制的探讨

[目的]通过观察莪蚕健胃方对胃癌前病变大鼠胃黏膜组织细胞增殖、凋亡及Bcl-2蛋白表达的影响,探讨莪蚕健胃方治疗胃癌前病变的作用机制.[方法]采用N-甲基-N-硝基-N-亚硝基胍(MNNG)配合饥饱失常法诱导造模.设空白对照组,模型对照组,莪蚕健胃方大、中、小剂量组,进行常规病理检测,采用免疫组化SP法、TUNEL法检测胃黏膜组织细胞增殖核抗原(PCNA)、Bcl-2蛋白及凋亡指数(AI)的表达情况.[结果]莪蚕健胃方各剂量组胃黏膜组织病理学变化,中、重度异型增生率与模型对照组相比明显降低(均P＜0.05);莪蚕健胃方能明显下调胃癌前病变组织细胞的PCNA、Bcl-2的表达,上调AI.[结论]莪蚕健胃方对大鼠实验性胃黏膜癌前病变有逆转作用,抑制细胞增殖、诱导细胞凋亡可能是该方的作用机制之一.     

左旋精氨酸甲酯及左旋精氨酸对应激状态下胃黏膜耐受性细胞保护作用的影响

目的：探讨内源性一氧化氮（NO）在应激状态下胃黏膜耐受性细胞保护中的作用及其可能的机制。方法：以重复浸水束缚应激（WRS）制作动物模型,以左旋精氨酸甲酯（L－NAME）或左旋精氨酸（L－Arg）抑制或促进内源性NO的合成,动态检测胃黏膜血流量（GMBF）、溃疡指数（UI）、黏膜一化氮含量的变化。结果：重复应激后,实验对照组大鼠UI明显下降,同时GMBF上升,黏膜内NO含量增高;L－NAME使WWRS引起的胃黏膜损伤加重,消除了GMBF的递增趋势,黏膜NO含量下降;而L－Arg可减轻WRS造成的黏膜损伤,GMBF、黏膜NO含量增相应增加;GMBF、UI、黏膜NO含量变化之间有相关关系。结论：内源性NO通过调节GMBF而介导耐受性细胞保护作用,L－NAME抑制其合成,延缓这一作用,L－Arg增加其合成,促进该作用。     

胃炎灵对大鼠胃粘膜保护作用的研究

目的 :探讨胃炎灵对实验大鼠胃粘膜损伤的保护作用及可能机制。方法 :在无水乙醇形成大鼠胃粘膜损伤模型后 ,应用中药胃炎灵治疗并观察胃粘膜病理变化、炎症程度、溃疡指数 (UI)及溃疡面积 ,并检测胃粘膜氨基乙糖及前列腺素 E2 (PGE2 )含量。结果 :治疗组胃粘膜充血、水肿、坏死、炎症程度、UI及溃疡面积较对照组明显减少 (P<0 .0 5 ) ,两组胃粘膜氨基乙糖及 PGE2 对照差异亦有显著性意义 (P<0 .0 5 )。结论 :胃炎灵对胃粘膜有良好的细胞保护作用 ,其机制可能为该药抑制炎症反应 ,提高氨基乙糖含量 ,增加 PGE2 的合成。     

The role of the vagus nerve in the protective action of acid inhibitors on ethanol-induced gastric mucosal damage in rats

The role of vagus in the actions of different acid inhibitors on ethanol-induced gastric damage and mucosal blood flow (GMBF) changes was studied in anaesthetized rats, using an ex vivo stomach chamber preparation. Subdiaphragmatic bilateral vagotomy decreased the basal gastric acid secretion and GMBF; it also intensified ethanol-evoked lesions in the glandular mucosa. Misoprostol, omeprazole and cimetidine produced a similar degree of reduction in acid output. Misoprostol given subcutaneously (s.c.) (50 micrograms/kg), or added to the incubation solution (12.5 micrograms) for 15 min, markedly prevented ethanol-induced lesion formation and reduction in GMBF. The reversing effect of s.c. injection of misoprostol on either lesion formation or on GMBF reduction was attenuated by vagotomy. Omeprazole protected against lesion formation only when present in the incubation solution (12.5 mg) of ex vivo chamber preparations of both vagus-intact and vagotomized animals, but the effect was significantly less in the latter group. The drug also prevented the depressive action of ethanol in vagus-intact animals. Cimetidine pretreatment (50 mg s.c. or 12.5 mg in incubation solution), however, did not modify the effects of ethanol on lesion formation and the GMBF. The findings indicate that the three different types of acid inhibitors exert different actions on ethanol-induced gastric mucosal damage, although they produced similar inhibition of acid output. Vagotomy lowers the GMBF and attenuates the antiulcer action of misoprostol and omeprazole, especially when the drugs are given by the parenteral route.     

尼美舒利抑制乙基硝基亚硝基胍诱导大鼠胃癌癌前病变的作用机制

目的:探讨选择性环氧合酶-2(COX-2)抑制剂尼美舒利在乙基硝基亚硝基胍(ENNG)诱导大鼠胃癌癌前病变发展过程的作用以及可能机制.方法:6周龄♂Wistar大鼠给予浓度为100 mg/L的ENNG溶液饮用14 wk后,使用浓度为300 m g/L和1 200 mg/L的尼美舒利溶液由大鼠自由饮用,分别在喂养14、26和38 wk后观察大鼠胃黏膜病变.使用免疫组织化学的方法观察大鼠病变胃黏膜COX-2蛋白、Bcl-2蛋白以及PCNA的表达,TUNEL法检测大鼠胃黏膜细胞凋亡.结果:药物干预的大鼠胃癌癌前病变的发生率显著低于对应的非用药组(P<0.05);药物干预组大鼠病变胃黏膜的COX-2蛋白和Bcl-2蛋白表达分别为17.6%,35.3%,显著低于非用药组的60%和84%(P<0.05);增殖指数18.9±4.57显著低于非用药组49.43±7.92(P<0.05);凋亡指数13.6±1.82显著高于非用药组2.12±0.53(P<0.05);COX-2蛋白和Bcl-2蛋白与PCNA的表达以及凋亡指数具有相关性(P<0.01).结论:选择性COX-2抑制剂尼美舒利能有效抑制ENNG诱导的大鼠胃癌癌前病变的发展,其机制可能是通过抑制COX-2、Bcl-2蛋白的表达,从而抑制病变胃黏膜细胞的增殖以及诱导其凋亡.     

硫氧还蛋白-1在急性坏死性胰腺炎并急性胃黏膜损伤中的作用

目的探讨硫氧还蛋白-1（TRX-1）在实验性急性坏死性胰腺炎（ANP）并急性胃黏膜损伤发病机制中的作用以及抗氧化剂褪黑素对其的影响。方法72只大鼠随机分为对照组（C组,n=24）、ANP组（A组,n=24）和褪黑素干预组（M组,n=24）。A组分3次腹腔内注射6％L-精氨酸（L—Arg）1．5g／kg建立ANP模型;C组同法注射等量生理盐水;M组于首次注射L—Arg前0．5h腹腔内注射1％褪黑素50μg／kg。各实验组大鼠于末次腹腔内注射后6h、12h和24h分批处死。光镜下观察胰腺和胃组织并进行病理学评分,采用免疫组化检测TRX-1在胃黏膜的表达,并检测胃黏膜中MDA、MPO的含量。结果A组各时点胃黏膜TRX-1的染色积分及MDA、MPO的含量明显高于C组（P均〈0．05）;M组各时点胃黏膜中TRX一1的染色积分及MDA、MPO的含量明显低于A组（P均〈0．05）,胰腺和胃组织病理改变较A组明显减轻（P均〈0．05）。结论内源性的TRX-1可能是胃黏膜组织抵御氧化应激损伤的重要因子之一,TRX-1的表达量可能与组织氧化应激损伤的严重程度有关。外源性的褪黑素在ANP时可能通过其抗氧化作用,减轻胃黏膜氧化应激损伤的程度,对胃黏膜有一定的保护作用。     

Role of TFF in healing of stress-induced gastric lesions

AIM: To determine the changes of pS2 and ITF of TFF expression in gastric mucosa and the effect on ulcer healing of pS2, ITF to Water-immersion and restraint stress (WRS)in rats.METHODS: Wistar rats were exposed to single or repeated WRS for 4 h every other day for up to 6 days. Gastric mucosal blood flow (GMBF) was measured by LDF-3 flowmeter and the extent of gastric mucosal lesions were evaluated grossly and histologically. Expression of pS2 and ITF mRNA was determined by RT-PCR. Immunohistochemistry was used to further detect the expression of pS2 and ITF.RESULTS: WRS applied once produced numerous gastric mucosal erosions, but the number of these lesions gradually declined and GMBF restored at 2, 4, 8 h after stress. The area of gastric mucosal lesion was reduced by 64.9 % and GMBF was increased by 89.8 % at 8 h. The healing of stress-induced ulcerations was accompanied by increased expression of pS2 (0.51±0.14 vs0.77±0.11, P＜0.01) and ITF (0.022±0.001 vs 0.177±0.010, P＜0.01). The results were demonstrated further by immunohistochemistry of pS2(0.95±0.11 vs1.41±0.04, P＜0.01) and ITF (0.134±0.001 vs 0.253±0.01,P＜0.01). With repeated WRS, adaptation to this WRS developed, the area of gastric mucosal lesions was reduced by 22.0 % after four consecutive WRS. This adaptation to WRS was accompanied by increased GMBF (being increased by 94.2 %), active cell proliferation in the neck region of gastric glands, and increased expression of pS2 (0.37±0.02 vs 0.77±0.01, P＜0.01) and ITF (0.040±0.001 vs0.372±0.010, P＜0.01). The result was demonstrated further by immunohistochemistry of pS2 (0.55±0.04 vs 2.46±0.08, P＜0.01) and ITF (0.134±0.001 vs0.354±0.070,P＜0.01).CONCLUSION: TFF may not only participate in the early phase of epithelial repair known as restitution(maked by increased cell migration),but also play an important role in the subsequent, protracted phase of glandular renewal(made by cell proliferation).     

胃舒散对大鼠慢性胃炎的治疗作用

[目的]研究胃舒散对大鼠慢性胃炎的治疗作用,并探讨其机制。[方法]用2%水杨酸钠结合饥饱失常等综合因素诱发大鼠实验性慢性胃炎模型,观察不同剂量胃舒散对其治疗作用。采用光镜和扫描电镜观察胃的组织学改变,用滴定法测定胃液游离胃酸,化学发光法测定胃组织超氧化物歧化酶(SOD)活性和丙二醛(MDA)水平。[结果]胃舒散(3.0 g/kg,1.5 g/kg)明显减轻了大鼠慢性胃炎程度,降低胃黏膜炎症指数并增加上皮层厚度,提高胃组织SOD活性,降低MDA水平(P<0.05),但对游离胃酸无明显作用。[结论]胃舒散对大鼠实验性慢性胃炎有治疗作用,其机制与抗氧化、保护胃黏膜细胞有关,但与胃酸分泌无关。