【作者】 钱俊；

【导师】 卢亦成；

【作者基本信息】 第二军医大学 ， 外科学， 2008， 博士

【摘要】 目的:本实验拟通过建立大鼠颅脑外伤致应激性溃疡模型,探讨(1)胃粘膜血流量、胃液PH值与胃粘膜损伤指数的关系;(2)中枢白介素6在应激大鼠下丘脑的表达,以及参与应激性溃疡发生的机制;(3)c-Jun氨基末端激酶(JNK)信号通路激活是否参与了应激性溃疡的形成,以及其通路抑制剂能否减轻胃粘膜的损伤。方法:采用液压打击法建立大鼠颅脑外伤并发应激性溃疡模型,将20只雄性SD大鼠随机等分为对照组、致伤1小时组、致伤6小时组和致伤12小时组,每组5只,测定各组大鼠胃液PH值、胃粘膜血流量、胃粘膜损伤指数,并观察胃粘膜大体及光镜下组织病理学变化。采用免疫组化、Westernblot的方法检测致伤后下丘脑中枢性白介素6的表达与分布;致伤后胃粘膜p-JNK的表达与分布。设立抑制剂组,通过观测抑制剂组胃液PH值、胃粘膜血流量、胃粘膜损伤指数以及胃粘膜大体及光镜下组织病理学变化,明确抑制剂能减轻胃粘膜损伤的作用。结果:(1)致伤后1小时即出现胃粘膜损伤,并且胃粘膜损伤指数随时间的延长而不断增加,损伤程度不断加重;致伤后1小时有血流量的暂时性增加,处于波峰,此后逐渐下降,6小时后趋于平稳,但致伤后6小时和12小时组仍较对照组降低;致伤后1小时胃液PH值明显降低,此后PH值继续下降,到致伤后6小时处于最低点,致伤后12小时胃液PH值较致伤后1小时和6小时有升高,但各组较对照组仍有明显降低;应激性溃疡大鼠胃液PH值与胃粘膜损伤指数不呈完全线性负相关,但各实验组胃液PH值较对照组有明显减低,而胃粘膜血流量与胃粘膜损伤指数呈负相关。(2)IL-6免疫反应阳性细胞广泛分布于应激大鼠下丘脑水平的神经细胞中,在室旁核附近分布尤为密集。(3)免疫组化发现在溃疡损伤部位组织上皮细胞p-JNK呈强烈阳性反应,c-Jun氨基末端激酶(JNK)信号通路抑制剂SP600125干预能显著减轻胃粘膜的损伤。结论:(1)本实验通过液压打击致颅脑外伤后建立了脑外伤后应激性溃疡模型。(2)应激性溃疡大鼠胃液PH值与胃粘膜损伤指数不呈完全线性负相关,但各实验组胃液PH值较对照组有明显减低,而胃粘膜血流量与胃粘膜损伤指数呈负相关。(3)中枢IL-6在液压打击致应激性溃疡大鼠下丘脑室旁核(PVN)附近有明显表达,其可能是通过室旁核(PVN)介导中枢胆碱能神经元的兴奋,HPA轴的激活以及5-HT系统的代谢增强,参与应激过程中应激性溃疡发生的某种病理生理机制。(4)在应激性溃疡中c-Jun氨基末端激酶(JNK)信号通路被激活,参与了应激性溃疡的发生。(5)JNK信号通路抑制剂SP600125可改善应激性溃疡大鼠胃粘膜的损伤,JNK信号通路抑制剂作为一种有效的手段,有可能对今后应激性溃疡的治疗提供了新的治疗思路,为临床药物的开发提供了重要指引,可能预示着新的治疗策略。更多还原

【Abstract】 Objective:Through the establishment of stress ulcer model of the rats induced by traumatic brain injury in the study,we want to know:(1) the relationship between gastric mucosal blood flow,gastric juice PH value and gastric mucosal injury index;(2)the expression of Central interleukin-6 in the rat hypothalamus stress,as well as the mechanism in stress ulceration;(3) C-Jun N-terminal kinase(JNK) signal pathway is or not involved in the activation of stress ulcer formation,as well as its pathway inhibitors can or can’t reduce gastric mucosal injury.Methods:stress ulcer model is established by fluid percussing injury.20 male SD rats were randomly divided into control group,one hour group,six hours group and 12 hours group after injuried(n=5).In each group of rats gastric PH value,gastric mucosal blood flow,gastric mucosal injury index are measured,and observed the histology of gastric mucosa.The expression and distribution of IL-6 in hypothalamus and p-JNK in gastric mucosal are detected by Immunohistochemistry and Westernblot.We establish a inhibitor group in order to know whether inhibitors can or not reduce gastric mucosal injury by the observation of PH value,gastric mucosal blood flow,and the histology.Results:(1) One hour after injury,we found the injury in the gastric mucosa.And the condition of injury became worse as time passed.The UI was increased.One hour after the injury there was a temporary increase in blood flow.It’s the peak.Then the blood flow was declined and keeped stabilizing.But the blood flow was still lower than the blood flow of control group.One hour after the injury the PH value was rapidly declined.The the lowest point was at 6h.Then it was increased.But the PH value of experimental groups was obviously lower than the PH value of control group.They had no negative correlations between PH value of gastric juice and gastric mucosal injury.But the PH value of experimental groups was obviously lower.It shows potential negative correlations between the gastric mucosal blood flow and gastric mucosa damage.(2)IL-6 immunoreactive cells widely distributed in nerve cells of hypothalamus in the stressed rat,especially in the paraventricular nucleus.(3) We found in the epithelial cells of ulcer injury p-JNK was strongly positive response by Immunohistochemistry.c-Jun N-terminal kinase(JNK) signal pathway inhibitor SP600125 can significantly reduce gastric mucosal injury.Conclusion:(1) stress ulcer model is established by fluid percussing injury.(2) They had no negative correlations between PH value of gastric juice and gastric mucosal injury.But the PH value of experimental groups was obviously lower than the PH value of control group.It shows potential negative correlations between the gastric mucosal blood flow and gastric mucosa damage.(3) The expression of IL-6 near the hypothalamic paraventricular nucleus (PVN) was obvious,which may be through the paraventricular nucleus(PVN) mediated by the central cholinergic neurons excited,HPA axis,as well as the activation of 5-HT system metabolism increased stress involved in the process of stress ulceration in some pathophysiological mechanism.(4) The c-Jun N-terminal kinase(JNK) signal pathway is activated in Stress ulcer and participated in the occurrence of stress ulcer.(5) JNK signaling pathway inhibitors SP600125 reduce gastric mucosa damage of the rat in stress ulcer.As an effective means,it probably provide us a new idea of the treatment of stress ulcer.It maybe provide us very important guidelines for a new treatment strategy.更多还原