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1.
采用1-萘胺-8-磺酸(ANS)为疏水探针,对大鼠胃粘膜表面疏水性作了研究,结果表明:以ANS(25μmol/L)与胃粘膜表面刮取物(胃粘液凝胶层)混合后的萤光强度(正常为1.23±0.19RFU/胃)可代表该粘液层的疏水性;以不同浓度ANS与胃粘液混合后的萤光强度呈饱和趋势,可用Scatchard作图法求得粘液中ANS的最大萤光强度(2.467±0.638RFU/胃)和相对亲和系数(0.032±0.016),它们可分别代表胃粘液中疏水基团的总量和单个基团的疏水性,从而可阐明胃粘膜被盐酸损伤后凝胶层粘液的ANS萤光减弱,系其疏水基团总量减少,而非单个基团的疏水性改变所致。  相似文献   

2.
胃粘膜血流量对大鼠胃粘膜适应性细胞保护作用的影响   总被引:12,自引:2,他引:12  
阎长栋  顾洛 《生理学报》1996,48(5):469-476
采用氢气清除法测定胃粘膜血流量,观察大鼠胃内灌洗低浓度盐酸酒精后灌注高浓度盐酸酒精(0.6mol/LHCl+15%EtOH)对GMBF和胃粘膜损害的影响。以及GMBF在适应性细胞保护中的作用。结果如下:(1)先用低浓度盐酸酒精作为弱刺激灌注随之以高浓度盐酸酒精作为强刺激灌注,引起胃粘膜适应性保护现象,它表现为:大体操作和损伤深度分别比单独泊组减少47.09%和44.57%应性现象,它表现为:大体损  相似文献   

3.
幽门螺杆菌对胃粘膜损伤机制的实验研究   总被引:1,自引:0,他引:1  
实验采用HP 活菌悬液,制成大鼠HP 损伤性胃炎模型,以便观察HP 对胃粘膜的损伤机制。结果表明:实验组与对照组比较,胃粘膜损伤指数增高(P< 0.05) ,胃壁结合粘液量明显降低(P< 0.01) ,胃粘膜PGE2 和SS 的含量降低(P< 0.01) 。说明幽门螺杆菌对胃粘膜防御系统有明显的损伤作用。  相似文献   

4.
消溃灵对大鼠胃溃疡愈合时粘膜EGFR表达的影响   总被引:6,自引:0,他引:6  
为了研究中药消溃灵对消化性溃疡愈合的影响及其对胃粘膜保护作用,采用乙酸注射至大鼠胃窦部浆膜下形成慢性胃溃疡模型,测定溃疡指数,并用免疫组织化学的方法,观察表皮生长因子受体在溃疡周围粘膜的表达并进行图像分析。结果表明雷尼替丁组和消溃灵组溃疡指数显著低于模型组(P<0.01)。模型组和雷尼替丁组表皮生长因子受体较对照组增加(积分光密度值和阳性细胞占总面积的百分比为P<0.01),消溃灵组比模型组和雷尼替丁组进一步增加(积分光密度值为P<0.05,阳性细胞占总面积的百分比为P<0.01)。本文提示,消溃灵对表皮生长因子受体的表达有一定的促进作用,这可能是消溃灵促进胃溃疡愈合和胃粘膜保护作用的机理之一。  相似文献   

5.
在缺氧-再给氧条件下,观察了体外分离培养的大鼠脑微血管内皮细胞表面粘附分子ICAM-1的表达及中性粒细胞与内皮细胞粘附作用的改变。结果表明,单纯缺氧10h不引起内皮细胞ICAM-1的上调,再给氧6hI-CAM-1的表达升高(P<0.01),再给氧12h表达量增加了100%(P<0.01),此时中性粒细胞与内皮细胞的粘附作用也明显增强(P<0.01)。缺氧前用盐酸川芎嗪(2mg/ml)预处理内皮细胞可阻断ICAM-1的表达(P<0.01),同时也可降低PMN与内皮细胞的粘附(P<0.05)。结果提示,脑微血管内皮细胞在缺氧-再给氧刺激下可自身调节I-CAM-1的表达,为中性粒细胞与内皮细胞的粘附提供特异的结合位点。  相似文献   

6.
Sun Y  Xu GS  Liu WP  Xu NG 《生理学报》1999,(2):206-210
用酒精灌胃引起大鼠胃粘膜损伤模型,观察内皮衍生因子(NO/ET)的含量变化和电针对胃粘膜损伤调整作用,结果发现:酒精灌胃后,胃粘膜血流量(GMBF)、跨壁电位差,血NO含量降低(P〈0.01),血浆ET含量和胃粘膜损伤指数(LI)增高(P〈0.01)。L-精氨酸(L-Arg)或硝普钠(SNP)灌注预处理后(iv),NO含量和GMBF明显升高(P〈0.01),ET含量和LI指数下降(P〈0.01)。  相似文献   

7.
对95例胃癌组织进行DAKO-M1(DAKO-CD15)表达的免疫组织化学研究。结果发现,DAKO-M1在胃癌中的阳性率(86.3%)显著高于癌旁粘膜和正常胃粘膜(P<0.05和0.005)。其定位分布有3种类型:即腺腔缘型(A型)、胞膜型(M型)和胞浆型(C型)。胃非肿瘤性粘膜组织仅为A型。胃癌3型兼有,高分化癌A型(18.2%)和M型(61.4%)均显著高于低分化癌(P值均<0.005);低分化癌和粘液癌C型(各占72.0%和53.8%)均显著高于高分化癌(20.5%),P<0.005和0.025。DAKO-M1C型和M型淋巴结转移率(分别为97.1%和69.2%)均显著高于A型(33.3%)者,P<0.005和0.05。结果提示,DAKO-M1是判断胃癌分化水平、恶性程度及预测淋巴结转移的一种有用标志物  相似文献   

8.
本研究着重探讨表皮生长因子(EGF)对大鼠肺动脉的收缩作用及对肺动脉平滑肌细胞分裂增殖的影响。浓度为1×10-9-1×10-7mol/L的EGF可引起大鼠肺动脉剂量依赖性收缩(r=0.968,P<0,001),其Emax为100.6mg,EC50为11.96nmol/L。在同时存在0.5%胎牛血清(FCS)时,EGF能促进平滑肌细胞的3H-TdR参入率,该作用与剂量呈正相关(r=0.823,P<0.05),其EC50为6.5×1O-12mol/L。1×10-9mol/L的EGF+0.5%FCS能产生与10%FCS相当的促细胞分裂增殖能力(在培养的第1,3,5,7天,二者促分裂增殖能力相差不明显,P均>0.05,第9天时,前者大于后者,P<0.05)。1×10-9mol/LEGF单独存在时对平滑肌细胞未显示出明显的致分裂活性。上述作用提示ECF在某些肺血管病变如缺氧性肺动脉高压中可能有一定意义。  相似文献   

9.
本实验采用四氧嘧啶损伤大鼠胰岛β细胞,复制糖尿病动物模型。若预先腹腔注射汉防己甲素(100mg/kg)则可完全预防引发的糖尿病。预防组血糖(7.63±0.44mmol/L)明显低于对照组(25.46±1.21mmol/L,P<0.001);血清胰岛素水平(11.33±1.97μU/ml)高于对照组(7.13±0.45μU/ml,P<0.05);血浆胰高血糖素(66.85±5.07pg/ml)明显低于对照组(90.35±3.15pg/ml,P<0.01).口服葡萄糖耐量实验显示预防组耐糖功能较对照组明显改善,糖耐量曲线下血糖面积预防组(29.45±1.63ml·h/L)低于对照组(113.28±5.02mmol·h/L,p<0.001)。胰岛β细胞免疫组织化学染色结果显示,预防组胰岛β细胞数目及胰岛素分泌颗粒的含量均与正常大鼠胰岛相同,无形态学改变,而对照组胰岛内β细胞免疫反应阳性产物减少甚至消失。结果表明,汉防己甲素对四氧嘧啶引起的胰岛β细胞急性损伤有保护作用。  相似文献   

10.
在无血清和含1.0%、5.0%血清培养的新生大鼠心肌细胞标本上,去甲肾上腺素(NE,2.0μmol/L)使细胞蛋白质含量(Lowry法)分别比相应对照组增加40%、26%、19%(P均<0.01);细胞3H-亮氨酸参入量与NE浓度呈正性剂量依赖性,最大效应浓度为20.0μmol/L;无血清培养体系中,0.2、2.0、20μmol/L的NE使参入量分别比对照增加17.8%、353%、37.7%;1.0%血清培养体系中分别比对照增加16.2%、27.9%、31.6%(P均<0.05);哌唑嗪(2.0μmol/L)可阻断NE的促蛋白质合成作用,心得安(2.0μmol/L)则无此效应。提示在无血清或低浓度血清培养体系中,NE可促进心肌细胞蛋白质合成,增加细胞蛋白质含量,该作用可能是通过α1肾上腺素能受体介导。  相似文献   

11.
We investigated the gastroprotective effect of apricot kernel oil on ethanol induced gastric ulcer in rats. Male Wistar albino rats were divided into control, ethanol and apricot kernel oil + ethanol groups. The fatty acid composition of apricot kernel oil was determined using GC-MS. A gastric ulcer index was defined as the area percentage of the gastric mucosa consisting of ulcerated tissue. Gastric tissue was investigated by TUNEL staining for apoptosis, immunohistochemical iNOS staining, measurement of gastric IL-10 and IL-6 expression by ELISA and assays of catalase, malondialdehyde and superoxide dismutase. The ethanol group exhibited a higher gastric ulcer score, increased IL-6 level, increased number of inducible nitric oxide synthase-positive and TUNEL positive cells, and a higher MDA level compared to the control group. The apricot kernel oil + ethanol group exhibited significantly fewer gastric lesions compared to the ethanol group. Apricot kernel oil protects rat gastric mucosa against ethanol induced injury by its anti-inflammatory, anti-oxidative and anti-apoptotic effects, and might be useful for reducing the severity of gastric ulcers.  相似文献   

12.
The effect of prostacyclin on gastric mucosal protein, DNA and RNA content has been investigated, either administered alone or in the course of indomethacin and stress-induced experimental ulcer models. It seems that: The oral administration of 100 micrograms/kg prostacyclin caused a prevailing DNA increase (decrease of the RNA/DNA ratio) in the rat gastric mucosa. Indomethacin and stress (restraint) ulcer formation were also followed by a predominant mucosal DNA increase which was maintained even during PGI2 treatment. The observed changes in RNA/DNA ratios were interpreted as a sign of accelerated cell renewal.  相似文献   

13.
Gastric ulcer was elicited in rats by reserpine (5 mg x kg-1 sc.) administration. Ulcer formation (number and severity) was measured 6, 12, 18 and 24 hr after reserpine administration. At the time of killing of the animals, tissue levels of adenosine triphosphate (ATP), adenosine diphosphate (ADP), adenosine monophosphate (AMP), cyclic adenosine monophosphate (cAMP) were measured enzymatically and by radioimmunoassay in the gastric fundal mucosa. The sum of ATP + ADP + AMP (adenylate pool) and the ratio of ATP x ADP-1 were calculated. It was found that (1) the tissue levels of ATP, AMP, cAMP, sum of ATP / ADP + AMP (adenylate pool) and ratio of ATP x ADP-1 increased significantly in the gastric fundal mucosa 6 hr after reserpine administration, thereafter these values decreased gradually and significantly; (2) the tissue level of ADP increased significantly in the gastric fundal mucosa 6 hr after reserpine administration, meanwhile its level increased significantly at 18 and 24 hr; (3) the value of energy charge (ATP + 0.5 ADP x ATP + ADP + AMP-1) remained unchanged; (4) the peaks of biochemical alterations in the gastric fundus mucosa preceded he appearance of ulcers. It was concluded that (1) reserpine ulcer appears after an active metabolic response in the rat gastric fundal mucosa; (2) hypoxaemic damage in the gastric fundal mucosa can be excluded as a possible underlying mechanism of ulcer formation produced by reserpine administration; (3) before the appearance of reserpine ulcer, significant changes in the feedback mechanism, system, i.e. between the ATP--membrane ATPase--ADP and the ATP--adenylate cyclase--cAMP energy systems, can be observed in the rat gastric fundal mucosa.  相似文献   

14.
刘均利  张席锦 《生理学报》1989,41(5):523-528
本工作研究了巯基物质在消炎痛引起大鼠胃粘膜损伤中的可能作用。在胃粘膜损伤发生过程中、胃粘膜内非蛋白及蛋白结合的巯基物质含量均无明显降低。虽然半胱胺灌胃(132或264μmol)或皮下注射(132μmol)后均明显抑制消炎痛溃疡的发生,其抑制率分别为82%,92%和75%,但同样具有巯基的半胱氨酸却无保护作用。半胱胺(132μmol)皮下注射可使消炎痛大鼠胃酸分泌抑制46%,而灌胃则无此作用。两种途径给予的半胱胺均不影响胃壁结合粘液的分泌。这些结果表明,胃粘膜内巯基物质似不参与消炎痛的致溃疡过程。半胱胺在此种模型上虽有强烈的细胞保护作用,但似乎不是由于其分子上所带的巯基所致。因此,巯基物质在消炎痛引起的胃粘膜损伤模型上没有细胞保护作用。  相似文献   

15.
《Journal of Physiology》1997,91(3-5):189-197
There exists a considerable controversy in the literature with regard to the effect of either opiate receptor blockade or that of morphine in different gastric and intestinal ulcer models in the rat. We performed experiments to evaluate the effects of naloxone and morphine on gastric acid secretion and gastric mucosal damage in different experimental models of gastric mucosal injury, namely in indomethacin-, HCl (0.6N)- and ethanol (96%)-models. We found that: 1) 10 mg/kg naloxone ip given twice, effectively protected gastric mucosa against indomethacin (30 mg/kg ip) and against the acid-dependent injury caused by 0.6 N HCl (1 mL ig), but not against the non acid-dependent injury caused by 96% ethanol (1 mL ig); 2) morphine (10 + 10 mg/kg ip) increased ulcers in the HCl-model, but had no effect in the two other models; 3) this ulcer-aggravating effect of morphine in the HCl-model was blocked by pretreatment of 2 mg/kg ip naloxone; and 4) both naloxone (5 + 5 and 10 + 10 mg/kg ip) significantly decreased gastric acid secretion in 1-h pylorus ligated rats. We conclude that: 1) naloxone dose-dependently protects against the indomethacin- and HCl-, but not against the ethanol-induced gastric mucosal damage; 2) morphine aggravates the HCl-induced ulcerogenesis; and 3) both opiod receptor agonist and antagonist decrease gastric acid secretion.  相似文献   

16.
《Journal of Physiology》1997,91(3-5):151-171
Capsaicin, the pungent principle of hot pepper, because of its ability to excite and later defunctionalize a subset of primary afferent neurons, has been extensively used as a probe to elucidate the function of these sensory neurons in a number of physiological processes. In the rat stomach, experimental data provided clear evidence that capsaicin-sensitive (CS) sensory nerves are involved in a local defense mechanism against gastric ulcer. Stimulation of CS sensory nerves with low intragastric concentrations of capsaicin protected the rat gastric mucosa against injury produced by different ulcerogenic agents. High local desensitizing concentrations of capsaicin or systemic neurotoxic doses of the agent markedly enhanced the susceptibility of the rat gastric mucosa to later noxious challenge. Resiniferatoxin, a potent analogue of capsaicin possesses an acute gastroprotective effect similar to that of capsaicin in the stomach. The gastroprotective effect of capsaicin-type agents involves an enhancement of the microcirculation effected through the release of mediator peptides from the sensory nerve terminals with calcitonin gene-related peptide being the most likely candidate implicated. They do not depend on vagal efferent or sympathetic neurons or involve prostanoids. The gastric mucosal protective effect of prostacyclin is retained after systemic or topical capsaicin desensitization. Capsaicin-sensitive fibers are involved in the repair mechanisms of the gastric mucosa. A protective role for CS sensory nerves has also been demonstrated in the colon. In most studies, capsaicin given into the stomach of rats or cats inhibited gastric acid secretion. In humans, although recent studies provide evidence in favor of a beneficial effect of capsaicin on the gastric mucosa, an exact concentration-related assessment of the effect of the agent is still lacking.  相似文献   

17.
建立冰乙酸性大鼠胃溃疡模型,采用ABC法进行免疫组织化学染色,观察并探讨胃溃疡对胃壁中HAP1(huntingtin as-soc iated protein 1,HAP1)表达的影响。结果溃疡组大鼠胃壁中HAP1阳性细胞数目及光密度与正常进食的大鼠相比显著增多。  相似文献   

18.
Cigarette smoking is a major risk factor for gastric cancer and peptic ulcer. The aim of our study was to investigate the relationship between exposure to cigarette smoke and apoptosis in the rat gastric mucosa and the mechanism involved. Rats were exposed to different concentrations of cigarette smoke (0, 2, and 4%) once daily for a different number of 1 h periods (1, 3, 6, and 9 d). Apoptosis was identified by the terminal deoxy-transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) method and caspase-3 activity. The mucosal xanthine oxidase (XO) activity and p53 level were also measured. The results showed that exposure to cigarette smoke produced a time- and concentration-dependent increase in apoptosis in the rat gastric mucosa that was accompanied by an increase in XO activity. The increased apoptosis and XO activity could be detected after even a single exposure. In contrast, the level of p53 was elevated only in the later stage of cigarette smoke exposure. The apoptotic effect could be blocked by pretreatment with an XO inhibitor (allopurinol, 20 mg/kg intraperitoneally) or a hydroxyl free radical scavenger (DMSO, 0.2%, 1 ml/kg intravenously). However, neither of these treatments had any effect on the p53 level of the mucosa. In summary, we conclude that exposure to cigarette smoke can increase apoptosis in the rat gastric mucosa through a reactive oxygen species- (ROS) mediated and a p53-independent pathway.  相似文献   

19.
Reactive oxygen species and lipid peroxidation play a role in the pathogenesis induced by the non-steroidal anti-inflammatory drug indomethacin. Melatonin (MLT) protection against indomethacin-induced oxidative tissue injury was investigated in gastric mucosa and testis of rats. MLT was administered intragastrically (i.g.) 30 min before the administration to fasted rats of 20 mg indomethacin/kg rat given i.g.. The area of gastric lesion as well as thiobarbituric acid reactive substances (TBARS) and lactate dehydrogenase (LDH) activity were found to be significantly increased 4 h after administration of indomethacin in rat gastric mucosa and testis indicating acute oxidative injury. MLT pretreatment reduced gastric lesion area to 80% of the indomethacin-treated rats and reduced the rise in TBARS concentration. MLT treatment reduced the LDH activity increase in testis but not in gastric mucosa. In indomethacin-treated rats, both the cytosolic Cu,Zn superoxide dismutase (Cu,Zn-SOD) and mitochondrial Mn-SOD activities were significantly diminished in gastric mucosa as well as the total SOD activity in testis. In addition, glutathione (GSH) content in both tissues was markedly decreased following indomethacin treatment. Pretreatment with MLT significantly ameliorated both the inhibition of SOD activity and the decreased GSH content in both tissues. Thus, these results show the effective antiperoxidative and preventive actions of MLT against indomethacin-induced gastric mucosal damage and testicular oxidative injury and we propose that this action might be relevant for its use with other free radical generating drugs.  相似文献   

20.
Gastroduodenal ulcerations have worldwide distribution and the infection with Helicobacter pylori (HP) has been implicated in pathogenesis of this disease. The HP infection is usually accompanied by hypergastrinemia and enhanced generation of prostaglandins (PG), both implicated in the pathogenesis of peptic ulcerations but no study has been undertaken to assess the relationship between the HP infection and coexpression of gastrin and cyclooxygenases (COX), the rate limiting enzymes in the PG production. Since HP infection, usually accompanying peptic ulcerations, results in increased release of gastrin, a potent gastric mitogen that might be capable to induce COX-2 and to generate PG, we decided 1) to compare the seroprevalence of HP and its cytotoxic protein, CagA, in gastric ulcer patients with those in age- and gender-matched controls; 2) to determine the gene expression of gastrin and its receptors (CCK(B)-R) at the margin of gastric ulcer and in the mucosa of antrum and corpus before and after successful eradication of HP, 3) to assess the plasma levels and gastric luminal contents of gastrin before and after HP eradication and 4) to examine the mRNA and enzyme protein expression of COX-1 and COX-2 as well as the PGE2 generation in ulcer margin tissue and gastric antral and fundic mucosa before and after the HP eradication. The trial material included 20 patients with gastric ulcer and 40 age- and gender-matched controls. Anti-HP and anti-CagA IgG seroprevalence was estimated by specific antisera using ELISA tests. Gene expressions of gastrin, CCK(B)-R, COX-1 and COX-2 were examined using RT-PCR with beta-actin as a reference and employing Western blotting for COX-2 expression, while gastrin and PGE2 were measured by RIA. All gastric ulcers were located at smaller curvature within the antral mucosal area. The seroprevalence of HP, especially that expressing CagA, was significantly higher in gastric ulcers (85%) than in controls (62.5%). Both gastrin and CCK(B)-R mRNA were detected by RT-PCR in ulcer margin and gastrin mRNA was overexpressed in remaining antral mucosa, while CCK(B)-R mRNA was overexpressed in fundic mucosa of HP infected patients. Similarly, COX-2 mRNA and protein were found in margin of gastric ulcer and in the HP infected antral and fundic mucosa but not in the mucosa of HP eradicated patients in whom ulcers completely healed and gastrin was expressed only in antrum, CCK(B)-R only in corpus, while COX-1 was detected both in antrum and corpus. HP positive gastric ulcer patients showed about three times higher levels of plasma immunoreactive gastrin and about 50% higher luminal gastrin contents than the HP negative controls and this increased plasma and luminal gastrin was normalized following the HP eradication. A significant fall in gastrin and CCK(B)-R mRNA expression was noticed six weeks after HP eradication in gastric antral and fundic mucosa, while COX-2 mRNA completely disappeared after this treatment. We conclude that 1) HP infected gastric ulcer margin coexpresses gastrin, its receptors (CCK(B)-R), and COX-2; 2) HP infection may be implicated in gastric ulceration via increased release of gastrin that could be responsible for the overexpression of COX-2 that in turn could help ulcer healing through the stimulation of mucosal cell growth, restoration of the glandular structure and angiogenesis in the ulcer area and 3) gastrin produced in HP infected antral mucosa seems to be involved in the induction of COX-2 and PG production by this enzyme and this may contribute to the ulcer healing.  相似文献   

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