胃壁细胞H+-K+ATP酶mRNA基因表达的影响因素

促胃酸分泌因子、Hp感染及常用抑酸药物均可对H+-K+ATP酶mRNA基因表达产生影响;H+-K+ATP酶mRNA的改变继而可引起H+-K+ATP酶活性及壁细胞泌酸功能改变.     

白细胞介素-1β介导幽门螺杆菌相关胃癌发生的实验研究

目的 探讨白细胞介素(IL)-1β在幽门螺杆菌(Hp)相关胃癌发生中可能的作用机制.方法 以人胃永生化上皮细胞株(GES-1)和胃癌细胞株(AGS)为研究对象,采用四甲基偶氮唑盐比色法测定IL-1β对细胞增殖的影响,流式细胞术碘化丙啶单染法测定IL-1β对Hp(NCTC 11637)诱导细胞凋亡的影响.分别应用RT-PCR法和流式细胞术(荧光定量法)检测IL-1β对细胞环氧合酶-2(COX-2)mRNA和蛋白表达的影响.以兔离体壁细胞为研究对象,应用14C-氨基比林(14C-AP)摄取法检测IL-1β对组胺刺激壁细胞酸分泌的影响,应用RT-PCR法分析IL-1β对壁细胞H+-K+-ATP酶α亚基mRNA表达的影响.结果 IL-1β能刺激GES-1和AGS细胞增殖,抑制Hp诱导的GES-1和AGS细胞凋亡.IL-1β能诱导GES-1 COX-2表达,上调AGS细胞COX-2表达;诱导GES-1和AGS细胞COX-2蛋白表达上调(分别由1.016±0.020和1.070±0.034上调至1.485±0.220和1.501±0.182).IL-1β能抑制组胺刺激的离体壁细胞酸分泌,同时伴H+-K+-ATP酶α亚基mRNA表达下调.结论 IL-1β可能通过两条途径在Hp相关胃癌发生中起作用:上调COX-2表达,破坏胃上皮细胞增殖、凋亡平衡和下调H+-K+-ATP酶表达以抑制壁细胞分泌.     

Nesfatin-1对离体胃黏膜细胞胃酸分泌的影响

目的:研究nesfatin-1对离体培养的大鼠胃黏膜酸分泌的影响,探讨nesfatin-1对H+/K+-ATP酶mRNA及蛋白表达的影响.方法:酶解法分离大鼠胃黏膜细胞,细胞免疫荧光检测法鉴定细胞.用不同浓度的nesfatin-1(10-4-10-1μmol/L)对胃黏膜细胞进行处理0、1、2、3、4h,设立空白对照组,以14C-氨基比林摄取为酸分泌指标,检测nesfatin-1对大鼠离体的胃黏膜细胞酸分泌的影响.用RT-PCR法及Western印迹法检测nesfatin-1对胃黏膜细胞H+/K+-ATP酶alpha(α)亚基和beta(β)亚基mRNA及蛋白表达的影响.结果:Nesfatin-1在10-1μmol/L浓度下,在1、2h能够抑制离体培养的大鼠胃黏膜细胞的酸分泌.Nesfatin-1(10-1μmol/L)在1、2、3h均能够抑制H+/K+-ATP酶α亚基mRNA表达水平;在1、2h能够抑制H+/K+-ATP酶β亚基mRNA表达水平,分别与对照组相比,差异有统计学意义(均P<0.01).Nesfatin-1(10-4-10-1μmol/L)作用胃黏膜细胞2h时,呈剂量依赖性抑制α亚基和β亚基mRNA表达水平,分别与对照组相比,差异有统计学意义(均P<0.01).Nesfatin-1(10-1μmol/L)在1、2、3h能够抑制α亚基蛋白表达水平;在2、3h能够抑制β亚基蛋白表达水平,分别与对照组相比,差异有统计学意义(均P<0.01).Nesfatin-1(10-3-10-1μmol/L)作用胃黏膜细胞2h时,呈剂量依赖性抑制α亚基和β亚基蛋白表达水平,与对照组相比,差异有统计学意义(均P<0.01).结论:Nesfatin-1能抑制离体培养的大鼠胃黏膜细胞的酸分泌,有可能是通过下调H+/K+-ATP酶α亚基和β亚基的mRNA及蛋白表达的水平影响酸分泌.     

老年人胃壁细胞超微结构和氢-钾腺苷三磷酸酶增龄性变化

目的 了解老年人胃壁细胞超微结构、氢-钾三磷酸腺苷酶(H+ -K+ -ATP酶)亚基mRNA及蛋白的增龄性变化. 方法 选择无胃十二指肠疾病者50例为研究对象,其中中青年组(20～59岁)19例和老年组(≥60岁)31例,老年组中60～69岁11例,70～79岁10例,80岁以上10例.电镜下观察胃壁细胞的超微结构,采用荧光定量PCR测定胃壁细胞H+-K+ -ATP酶α亚基mRNA的表达,采用免疫印记法检测胃壁细胞H+-K+ -ATP酶β亚基蛋白的表达,并分别比较其增龄性变化. 结果 电镜下观察各年龄组胃壁细胞及与泌酸功能相关的细胞器形态分布无明显差异,定量测定线粒体面积分数中青年组为(48.4±7.5)％,与老年组(50.6±7.6)％比较,差异无统计学意义(t=-0.775,P=0.444);管泡系统面积分数中青年组为(13.8±4.1)％,老年组为(12.2±4.7)％,差异无统计学意义(t=0.984,P=0.332).老年组H+ -K+ -ATP酶α亚基mRNA的表达(t=-3.682,P=0.001)及H+-K+-ATP酶β亚基蛋白(t=-3.389,P=0.004)均显著高于中青年组,但中青年组与老年各年龄组间趋势方差分析显示,H+ -K+ -ATP酶mRNA的表达(F=1.522,P=0.24)及H+-K+ -ATP酶蛋白的表达(F=2.32,P=0.114)差异无统计学意义. 结论 随增龄老年人胃壁细胞内与泌酸功能直接相关的细胞器无退化表现,H+-K+-ATP酶表达有增加趋势,提示健康老年人存在维持良好泌酸功能的超微结构和分子生物学物质基础.     

甲状腺功能减退大鼠心肌抗氧化能力及Na+-K+-ATP酶α1亚基mRNA表达的研究

采用低碘饮食建立甲状腺功能减退(甲减)动物模型,观察心肌抗氧化能力及Na+-K+-ATP酶α1亚基mRNA的变化,结果显示甲减大鼠心肌抗氧化能力下降,导致心肌过氧化损伤,心肌细胞萎缩,心脏内膜软骨化生,膜上参与代谢的ATP酶活性降低,Na+-K+-ATP酶α1亚基mRNA的表达下降.     

雷贝拉唑抑制大鼠胃壁细胞泌酸功能的机制研究

目的 探讨质子泵抑制剂雷贝拉唑对大鼠胃壁细胞泌酸功能的抑制作用.方法 将72只SD大鼠分成对照组(0.9%氯化钠溶液)、雷贝拉唑低剂量组(10 mg/kg)和雷贝拉唑高剂量组(20 mg/kg),每组24只.分别在1、2、4、6、12和24 h每组各处理4只大鼠.用氢氧化钠滴定法测定大鼠胃内pH值,比色法测定胃壁细胞内H+-K+-ATP酶活性,电镜下观察胃壁细胞超微结构的改变.结果 与对照组(1.97±0.30)相比,雷贝拉唑低剂量组(3.37±0.97)和高剂量组(5.96±0.26)在给药后1 h内胃液pH值显著升高(P<0.01),壁细胞H+-K+-ATP酶活性明显抑制(3.28±0.41比1.47±0.27和0.92±0.07,P<0.05).而且在给药12 h的差异仍有统计学意义(P<0.01).电镜下胃壁细胞超微形态改变与胃液pH值和壁细胞H+-K+-ATP酶活性变化相符.雷贝拉唑低剂量组与高剂量组在抑酸作用和起效时间方面差异有统计学意义(P<0.01).结论 壁细胞超微结构的变化和H+-K+-ATP酶活性能准确反映壁细胞的泌酸情况,雷贝拉唑能迅速强效抑制大鼠壁细胞的泌酸功能,且与剂量有关.     

胃壁细胞H^＋-K^＋ATP酶mRNA基因表达的影响因素

促胃酸分泌因子、Hp感染及常用抑酸药物均可对H^ -K^ ATP酶mRNA基因表达产生影响；H^ -K^ ATP酶mRNA的改变继而可引起H^ -K^ ATP酶活性及壁细胞泌酸功能改变。     

Aβ_(1～42)及二氮嗪预处理对神经细胞Na~+-K~+-ATP酶β亚基蛋白表达的影响

目的探讨Aβ1~42及二氮嗪预干预对神经细胞Na+-K+-ATP酶β亚基蛋白表达的影响。方法原代培养大鼠皮层海马神经细胞,随机分为空白对照组、Aβ1~42组(2μmol/L)、二氮嗪(50μmol/L)预处理1 h后Aβ1~42组、单独二氮嗪预处理组,各组又分为24、72 h两个时间点,采用免疫荧光及免疫印迹法检测干预后不同培养时间细胞Na+-K+-ATP酶β亚基蛋白表达水平的变化。结果免疫荧光显示:Aβ1~42作用细胞72 h降低了Na+-K+-ATP酶β亚基荧光强度;而经二氮嗪预处理后Aβ1~42作用72 h,与单独Aβ1~42组相比较荧光强度有所增强。Western印迹显示:二氮嗪预处理神经细胞1 h协同Aβ1~42作用24 h后及单独二氮嗪组Na+-K+-ATP酶β亚基的蛋白表达明显低于对照组及单独Aβ1~42组(P0.01)。Aβ1~42作用神经细胞72 h后,Na+-K+-ATP酶β亚基蛋白表达较对照组显著降低(P0.05);二氮嗪预处理1h协同Aβ1~42共同作用于神经细胞72 h后,与单独Aβ1~42组相比较,增加了Na+-K+-ATP酶β亚基蛋白表达量(P0.05)。结论 Aβ1~42作用72 h,Na+-K+-ATP酶β亚基蛋白表达量降低,二氮嗪预处理1 h协同Aβ1~42共同作用于神经细胞72 h,Na+-K+-ATP酶β亚基蛋白表达量升高。     

幽门螺杆菌感染及根除对胃壁细胞及氢-钾ATP酶mRNA基因表达的影响

目的　利用人类幽门螺杆菌 (Hp)慢性感染小鼠模型研究根除Hp前后胃壁细胞及H+ K+ ATP酶mRNA基因表达的变化。方法　 2 0只BALB/C小鼠 ,每天 0 .4mlHp菌液灌胃 ,连续 5d ,2个月后将慢性Hp感染小鼠随机分为两组 ,根除组予克拉霉素按13.5mg·kg-1·d-1分两次灌胃 ,连续 7d ;感染组予生理盐水 ,用量方法同上。 1个月后处死动物 ,取胃黏膜用尿素酶试验、Giemsa染色检查 ;电镜观察壁细胞形态 ,用图像分析软件分别计算出两组分泌小管面积分数 ;用RT PCR测定H+ K+ ATP酶mRNA基因表达情况。结果　感染组动物胃黏膜尿素酶试验及Giemsa染色均为阳性 ;图像分析软件结果显示 ,感染组分泌小管面积分数为 (2 .2 0± 0 .0 6 ) / 10 4,根除组为 (3.2 0± 0 .0 6 ) / 10 4,两组比较差异有显著性 ;用RT PCR测定H+ K+ ATP酶mRNA基因表达结果显示 ,感染组为 0 .84± 0 .12 ,根除组为1.17± 0 .19,两组比较差异有显著性。结论　Hp感染可致胃酸分泌减少 ,而根除后明显增加 ,增加的原因可能与Hp根除后 ,下调了H+ K+ ATP酶mRNA基因表达因素有关。     

兰索拉唑对离体壁细胞酸分泌的影响

目的应用兔离体壁细胞为模型,研究兰索拉唑体外抑酸效果.方法应用细胞淘洗与连续密度梯度离心相结合的方法分离兔胃黏膜壁细胞,以14C氨基比林摄取为酸分泌指标,观察西咪替丁及兰索拉唑对离体壁细胞组胺诱导的酸分泌的影响.结果壁细胞纯度达80%以上进行实验,兰索拉唑能明显抑制离体壁细胞组胺诱导的酸分泌,对组胺刺激酸分泌的50%抑制量(IC50)为9.59×10-8mol/L,明显高于H2受体拮抗剂(3.70×10-5mol/L).结论兰索拉唑对兔离体壁细胞组胺诱导的酸分泌具明显的抑制作用,效果优于西咪替丁;本研究为国内开展新的抑酸剂基础与临床研究提供了新方法.     

生长抑素抑制酸分泌的机制研究

目的探讨生长抑素-14(SS-14)通过何种受体亚型抑制兔离体壁细胞组胺诱导的酸分泌.方法利用经纯化的离体壁细胞为研究模型,以14C-氨基比林摄取为指标,观察SS-14及某些生长抑素受体亚型特异性激动剂对组胺诱导的酸分泌的影响;用反转录聚合酶链反应方法(RT-PCR)及原位杂交方法(ISH)研究壁细胞生长抑素受体亚型的表达.结果SS-14、奥曲肽以及生长抑素Ⅱ型受体特异性激动剂NC8-12(10-9～10-7mol/L)均能明显抑制组胺(10-6mol/L)诱导的酸分泌(P《0.01),而生长抑紊Ⅲ、Ⅳ型受体激动剂在相同浓度下对组胺诱导的酸分泌无明显抑制作用(P》0.05);RTPCR方法扩增出了生长抑素Ⅱ型受体(SSR2)的特异片段;用ISH方法确定了离心涂片的壁细胞以及胃黏膜冰冻组织切片的壁细胞上有SSR2基因表达.结论在国内外首次证明SSR2介导生长抑素对兔离体壁细胞组胺诱导的酸分泌的抑制作用;首次证明壁细胞有SSP2的基因表达.     

H+/K+-adenosine triphosphatase mRNA in gastric fundic gland mucosa in patients infected with Helicobacter pylori.

BACKGROUND: How Helicobacter pylori infection affects gastric acid secretion has not been made clear. This study aimed to elucidate the effects of H. pylori infection on H+/K+-adenosine triphosphatase (ATPase) mRNA in gastric fundic gland mucosa. METHODS: Twenty patients with chronic gastritis and H. pylori infection were treated with lansoprazole and antibiotics. Before and 1 month after treatment gastroduodenoscopy was performed, and changes in the amount of H+/K+-ATPase mRNA in the fundic gland mucosa, gastric juice pH, and serum gastrin levels were determined. RESULTS: The amount of H+/ K+-ATPase mRNA in the fundic gland mucosa was increased in patients with eradication of H. pylori, in whom significant decreases in gastric juice pH and serum gastrin levels were observed. No significant changes were observed in patients without eradication of H. pylori. CONCLUSIONS: These results suggest that one of the mechanisms by which H. pylori infection suppresses acid secretion is by the inhibition of proton pump synthesis in parietal cells.     

H+/K+-Adenosine Triphosphatase mRNA in Gastric Fundic Gland Mucosa in Patients Infected with Helicobacter pylori

Background: How Helicobacter pylori infection affects gastric acid secretion has not been made clear. This study aimed to elucidate the effects of H. pylori infection on H+/K+-adenosine triphosphatase (ATPase) mRNA in gastric fundic gland mucosa. Methods: Twenty patients with chronic gastritis and H. pylori infection were treated with lansoprazole and antibiotics. Before and 1 month after treatment gastroduodenoscopy was performed, and changes in the amount of H+/K+-ATPase mRNA in the fundic gland mucosa, gastric juice pH, and serum gastrin levels were determined. Results: The amount of H+/K+-ATPase mRNA in the fundic gland mucosa was increased in patients with eradication of H. pylori, in whom significant decreases in gastric juice pH and serum gastrin levels were observed. No significant changes were observed in patients without eradication of H. pylori. Conclusions: These results suggest that one of the mechanisms by which H. pylori infection suppresses acid secretion is by the inhibition of proton pump synthesis in parietal cells.     

The effect of arachidonic acid and its metabolites on acid production in isolated human parietal cells

The effect of arachidonic acid and its metabolites on the histamine-stimulated acid production in human isolated parietal cells provenient from endoscopic biopsies was examined. 14C-aminopyrine (14C-AP) accumulation in the parietal cells was used for evaluation of acid production. Histamine dose-dependently increased AP uptake. Histamine stimulation (taken as 100% at 10(-5) M) was significantly inhibited by prostaglandin (PG) E2 to 66 +/- 7% at 10(-8) M, 42 +/- 8% at 10(-6) M, and 13 +/- 10% at 10(-4) M (mean +/- SEM, n = 10). PGF2 alpha, PGD2, and PGI2 showed significant inhibitory effects only at very high concentrations (10(-5)-10(-4) M). Leukotriene (LT) B4 and LTC4 were without effect. The basal acid production (taken as 0%) was lowered significantly by 10(-6) M arachidonic acid to -20 +/- 7.4% (p less than 0.02, n = 10), and the histamine-stimulated (10(-6) M) acid production from 100% to 64 +/- 7.2% (p less than 0.001, n = 10). Aspirin (10(-3) M) increased basal (45 +/- 9.6%, p less than 0.001, n = 10) and histamine-stimulated (10(-6) M) acid production (164 +/- 16.3%, p less than 0.001). It is concluded that PGE2, the major product from arachidonic acid metabolism in the human gastric mucosa, is a significant inhibitor of the histamine-stimulated human parietal cell and may, in humans, play a role as a local physiologic inhibitor of acid secretion.     

胃酸分泌的调节

胃酸分泌是一个动态且复杂的过程,壁细胞H＋-K＋-ATP酶是泌酸的最终和最关键环节。刺激胃酸分泌的主要途径包括旁分泌（肠嗜铬细胞分泌的组胺）、内分泌（G细胞分泌的胃泌素）、神经内分泌（肠神经节后神经纤维分泌的胆碱能）,上述因子结合壁细胞膜上相应受体,通过细胞内第二信使（钙离子、cAMP等）激活蛋白激酶．使壁细胞胞浆管状囊泡运载H＋-K＋-ATP酶向壁细胞顶膜移行并最终使酶嵌入壁细胞顶膜,在H＋-K＋-ATP酶的作用下与胞外K＋交换,泵出H＋。本文就壁细胞胃酸分泌相关受体及其信号通路作一概述。     

Morphological and functional restoration of parietal cells in Helicobacter pylori associated enlarged fold gastritis after eradication

BACKGROUND/AIM: Helicobacter pylori infections are associated with hypochlorhydria in patients with pangastritis. It has previously been shown that eradication of H pylori leads to an increase in acid secretion in H pylori associated enlarged fold gastritis, suggesting that H pylori infection affects parietal cell function in the gastric body. The aim of this study was to evaluate the effects of H pylori infection on parietal cell morphology and function in hypochlorhydric patients. PATIENTS/METHODS: The presence of H pylori infection, mucosal length, and inflammatory infiltration were investigated in six patients with enlarged fold gastritis and 12 patients without enlarged folds. Parietal cell morphology was examined by immunohistochemistry using an antibody against the alpha subunit of H(+),K(+)-ATPase and electron microscopy. In addition, gastric acid secretion and fasting serum gastrin concentration were determined before and after the eradication of H pylori. RESULTS: In the H pylori positive patients with enlarged fold gastritis, fold width, foveolar length, and inflammatory infiltration were increased. In addition, the immunostaining pattern of H(+), K(+)-ATPase was less uniform, and the percentage of altered parietal cells showing dilated canaliculi with vacuole-like structures and few short microvilli was greatly increased compared with that in H pylori positive patients without enlarged folds. After eradication, fold width, foveolar length, and inflammatory infiltrates decreased and nearly all parietal cells were restored to normal morphology. On the other hand, altered parietal cells were negligible in H pylori negative patients. In addition, the basal acid output and tetragastrin stimulated maximal acid output increased significantly from 0.5 (0.5) to 4.1 (1.5) mmol/h and from 2.5 (1.2) to 13.8 (0.7) mmol/h (p<0.01), and fasting serum gastrin concentrations decreased significantly from 213.5 (31.6) to 70.2 (7.5) pg/ml (p<0.01) after eradication in patients with enlarged fold gastritis. CONCLUSION: The morphological changes in parietal cells associated with H pylori infection may be functionally associated with the inhibition of acid secretion seen in patients with enlarged fold gastritis.