【作者】 李玉梅；

【导师】 房殿春；

【作者基本信息】 第三军医大学 ， 内科学， 2002， 硕士

【摘要】 应激性溃疡(stress ulcer，SU)是各种临床危重疾病和严重心理障碍的常见并发症，具有较高的发病率和死亡率，其发生机制目前尚未完全清楚。近年来，国内外学者对其发生机制进行了一系列的实验和临床研究，取得了较大的进步。目前认为，SU的发生涉及胃粘膜保护机制的削弱，损伤因素作用的相对增强以及机体神经内分泌功能失调等诸多方面，是多因素综合作用的结果。胃酸是最常见的内源性损伤因子，在SU发生发展过程中起着不容忽视的作用。本课题采用水浸束缚应激的方法制作动物模型，研究应激状态下大鼠胃壁细胞超微结构和泌酸功能的动态变化，并观察奥美拉唑和西咪替丁等抑酸剂对应激状态下大鼠胃壁细胞超微结构和泌酸功能的影响，以探讨胃酸在SU发病中的意义。 本课题包括三部分内容，分述如下： 一、应激状态下大鼠胃壁细胞形态和泌酸功能的动态变化 目的：探讨应激状态下大鼠胃壁细胞超微结构和泌酸功能的动态变化及其与急性胃粘膜损伤之间的相关性。 材料与方法：本实验选用Sprague-Dwley(SD)雄性大鼠，参考Brodie DA的方法制备水浸-束缚应激(WRS)溃疡模型；观察WRS 1h、2h、4h大鼠胃粘膜损伤情况，按Guth标准评估胃粘膜损伤溃疡指数(UI)；采用pH／mV型pH计检测胃液pH值；用化学比色、无机磷测定的方法检测胃壁细胞H~+，K~+-ATP酶活性；并于光镜下观察胃粘膜组织病理学改变，于透射电镜下观察壁细胞超微结构变化。 结果：1．胃粘膜损伤情况：对照组未见损伤性改变，光镜下粘膜结构完整；应激1h组腺胃部见有少量斑点状糜烂、出血，UI为9.5±2.98，明显高于对照组(p<0.01)，光镜下可见表层粘膜部分坏死、脱落;应激2h组粘膜表面有少量血痴，腺胃部散在多量点线状糜烂、出血，Ul为22.5士3.16，明显高于对照组和应激lh组(p<0.01)，镜下可见粘膜表层多量坏死、脱落，局部腺体结构紊乱;应激4h组粘膜面见多量血痴，腺胃部弥漫性点线状出血、糜烂及溃疡形成，Ul高达35.0士3.93，明显高于前三组 (p<0 .01)，镜下可见粘膜明显出血、坏死、脱落、中断，溃疡呈火山口状，可深达粘膜肌层。胃粘膜损伤程度Ul与应激时间呈明显的正相关(二0.9876，p<0.01)，随应激时间延长，UI明显增加。2.胃液pH值检测情况;对照组胃液pH值为2.56士0.14;应激lh组为2.26士0.40，与对照组比较，差异无显著性(p>0.05);应激2h组pH值为1.81士0.25，与对照组比差异非常显著(p<0.01)，与应激lh组比差异也有显著性(p<0.05);应激4h组pH值为1.31士024，与前三组比差异均非常显著(p<0.01)。胃液pH值与uI之间呈明显负相关(r=一0.9987，p<0.01)。3.胃壁细胞H+，K气ATP酶活性检测:对照组H+，K气ATp酶活性为7.48士o.59U/mg prot;应激lh组为7.60士0.46U/mg prot，与对照组比较无明显差异(p>0.05):应激Zh组为7.81士0.24U/m 9 prot，与前两组比较差异无显著性(p>0.05);应激4h组为9.50士1.63U/m 9 prot，与前三组比较均有显著性差异(p<0.05)。4.壁细胞超微结构的变化:对照组壁细胞内可见大量散在分布的囊泡和管泡结构，分泌小管内绒毛稀少或缺如，呈静息状态;应激lh组壁细胞内见分泌小管绒毛短少，其周围有多量囊泡聚集，呈开始激活状态;应激Zh组壁细胞内分泌小管增多，绒毛增多增长，胞浆内囊泡明显减少，呈激活状态;应激4h组壁细胞内分泌小管密集，周围的囊泡基本消失，呈明显的泌酸活跃状态。胃酸分泌状态与壁细胞超微结构改变相一致。 结论:水浸束缚应激(WRS)动物模型制作非常成功;WRS可激活大鼠胃壁细胞，引起胃酸分泌增加;胃酸的分泌状态与壁细胞超微结构的改变相一致，并与胃粘膜损伤程度有明显相关性。提示胃酸在应激性溃疡的发生发展过程中具有重要意义。 二、应激结束后大皿胃壁细胞形态和功能的变化 目的:观察应激结束后大鼠胃壁细胞超微结构和泌酸功能的变化，以及受损胃粘膜的组织病理修复过程。 材料与方法:采用WRS的方法制作大鼠应激溃疡模型，将40只SD大鼠随机分成对照组、应激组、应激后24h、48h、72h组。对照组不施加应激，其它四组应激时间均为4h。采用上述同样方法检测胃粘膜损伤Ul、胃液pH和H+，K十一ATP酶活性，于光镜和透射电镜下，观察胃粘膜组织学变化及胃壁细胞超微结构改变。 结果:1.胃粘膜损伤修复情况:应激后24h、48h、72h组胃粘膜损伤Ul从35.0土3.93分别降到17.1士1.55、7.4士2.20与0，与应激组比及各组间比均有显著性差异(p<0.01)。光镜下，应激后24h组可见深达粘膜肌层的应激性溃疡，其基底部及周边粘膜明显充血;应激后48h组可见修复中的溃疡，其内见新生腺体出现;应激后72h组溃疡基本修复。2.胃液pH值检测:应激后24h、48h、72h组胃液pH值分别为2.50士0.24、2.32士0.36与2.37士0.19，较应激组(l .31士0.24)明显升高(p<0.01)，与对照组(2 .56士0.14)之间差异无显著性(p>0.05)。3.胃壁细胞H+，K十一ATP酶活性检测:应激后24h组为7.88士o27U/mg prot，与应激组(9.50士1.63U/mg prot)相比差异无显著性(p>0.05);应激后48h组为7.0更多还原

【Abstract】 Stress ulcer (SU) is a usual complication of clinical serious diseases and serious psychosis in clinic. It has a higher incidence and mortality, while its genesis mechanism is not very clear yet. At present, the scholars at home and abroad have performed a series of experiments and clinic studies on the genesis mechanism of SU and have made a great progress. It has been generally considered that many factors, such as weakened gastric mucosa defense, augmented impair factors and neurocrine imbalance, can induce SU. During the development of SU, gastric acid plays an important role and is believed the most common endogenetic damage factor. The purpose of this study was to investigate the dynamic changes of ultrastructure and function of gastric parietal cells and to observe the effects of omeprazole and cimetidine on the ultrastructure and function of gastric parietal cells in rats under water immersion-restraint stress (WRS) in order to probe the role of gastric acid during SU developing.1. The dynamic change of ultrastructure and function of gastric parietal cells in rats under stressObjective: To study the dynamic changes of ultrastructure and function of parietal cells in rats under stress and their correlation with acute gastric mucosal lesion.Methods: WRS model in SD rats was performed according to Brodie’s method described previously. The extent of gastric mucosal lesion was evaluated grossly and histologically at WRS 1h, 2h, 4h according to the Guth standard. The pH value of gastric juice was measured by the pH/mV meter pH. The H+, K+-ATPase activity was determined by chemical colorimetry and inorganic phosphate assay. The histopathological change of gastric mucosa wasobserved by light microscope (LM) and the ultrastructural change of parietal cells was observed by transmission electron microscope (TEM).Results: 1. Gastric mucosal lesion: there was no lesion in control and a little spot erosion or hemorrhage in WRS 1h group. The gastric mucosal ulcer index (UI) was higher in WRS 1h group (9.5 2.98) than in control (p<0.01). Some mucosal shedding and necrosis were observed under LM. A little bloodstain and some scattered spot or lineal erosions and hemorrhage were observed in WRS 2h group. The UI ( 22.5 3.16) was higher in this group than in the former (p<0.01), and lots of necrosis, shedding and confusion were observed. In WRS 4h group, more bloodstain and scattered spot or lineal erosions, hemorrhage and ulcer were observed. The UI (35.0 3.93) was much higher (p<0.01), and more necrosis, shedding, hemorrhage, interruption and crateriform ulcer were observed. There was a positive relationship between UI and stress time (r=0.9876, p<0.01). The UI increased significantly with prolonged stress time. 2. Gastric juice pH value: The pH value was 2.56 0.14 in control and 2.26 0.40 in WRS 1h group with no statistical significant (p>0.05). The pH value of 1.81 0.25 in WRS 2h group was lower than control(p<0.01) and WRS 1h group(p<0.05), and 1.31 0.24 in WRS 4h group much lower than in other groups(p<0.01). There was a negative relationship between UI and pH(r=-0.9987, p<0.01). 3. H+, K+-ATPase activity (U/mg prot): Enzyme activity was 7.48 0.59 U/mg prot in control and 7.60 0.46 U/mg prot in WRS 1h group with no statistical significant (p>0.05). Activity of 7.81 0.24 U/mg prot was higher in WRS 2h group than in the formers (p>0.05), and 9.50 1.63 U/mg prot in WRS 4h group much higher than in other groups (p<0.05). 4. Ultrastructural changes of parietal cells: A resting state showing plenty of tubulovesicles and little of intracellular canaliculi lined with rare microvilli was observed in control. The beginning secreting state displaying intracellular canaliculi lined with short and little microvilli and plenty of vesicles around it was observed in WRS 1h group. A secreting state showing the increasing intracellular canaliculi and microvilli and the decreasing vesicleswas observed in WRS 2h group. An active secreting state displaying intracellular canaliculi lined with numerous microv更多还原