构建基于体表神经源性渗出反应的急性胃黏膜损伤大鼠病情分级模型研究

Establishment of a grading model for acute gastric mucosal injury in rats based on cutaneous neurogenic exudation response

目的构建不同浓度梯度盐酸诱导下的急性胃黏膜损伤(acute gastric mucosal injury,AGMI)大鼠模型,并探讨尾静脉注射不同浓度及剂量的伊文思蓝(evans blue,EB)对大鼠生存率及体表渗出情况的影响。方法(1)将Wistar大鼠根据体重随机分配到5个组:150~180 g组、180~200 g组、200~250 g组、300~400 g组以及400~500 g组,并进一步根据盐酸浓度分为8个亚组,具体浓度为:0.40、0.45、0.50、0.55、0.60、0.65、0.70 mol/L盐酸组以及以生理盐水组作为对照,共40个小组,每小组3只,共计120只。评估各组大鼠造模后24 h生存率,并分析体重和盐酸浓度对大鼠生存情况的交互关系。在确定5个梯度盐酸浓度的基础上,采用苏木精-伊红(HE)染色法观察胃黏膜镜下的病理变化。(2)选择(1)结果中适合制备的最高盐酸浓度制备AGMI模型,随后,将大鼠随机分配到不同的EB浓度和剂量组中,具体分组:EB 1(0.5%,0.4 mL)组、EB 2(1%,0.1 mL/100 g)组、EB 3(1%,0.2 mL/100 g)组、EB 4(2%,0.1 mL/100 g)组、EB 5(2%,0.2 mL/100 g)组、EB 6(5%,0.1 mL)组,每组5只,共30只。评估注射EB后24 h内的生存率和体表渗出程度。结果(1)AGMI大鼠造模后症状随着盐酸浓度升高而加剧,0.65 mol/L和0.70 mol/L在各体重组中的24 h生存率均为0%。Kaplan-Meier生存曲线表明,不同盐酸浓度组大鼠的生存率存在显著性差异(P<0.001),且盐酸浓度与体重之间的交互作用对大鼠的存活时间产生显著影响(P<0.001),确定的5个梯度盐酸浓度为0.40、0.45、0.50、0.55、0.60 mol/L。组织学观察结果表明,AGMI大鼠胃黏膜炎性细胞浸润程度随盐酸浓度升高而加剧。(2)0.60 mol/L盐酸制备的AGMI大鼠,尾静脉注射5%EB(0.1 mL)后24 h生存率仅为40%。Kaplan-Meier生存曲线结果显示,EB不同浓度和注射量下AGMI大鼠的生存率无显著性差异(P>0.05)。体表渗出情况分析显示,EB 1组大鼠皮肤和眼睛颜色变化较淡,体表渗出点较少,而EB 4组、EB 5组大鼠皮肤颜色和渗出情况较明显。单因素方差分析进一步证实,EB 3组、EB 4组和EB 5组大鼠的体表EB渗出点数量显著多于EB 1组(P<0.05,P<0.01)。结论盐酸造模能够实现多个精确浓度梯度的设置。禁食后体重为180~200 g范围的大鼠,灌胃0.40~0.60 mol/L浓度可有效制备AGMI模型。尾静脉注射2%EB(0.2 mL/100 g),将有利于开展AGMI大鼠体表EB渗出点分布特征随时间和病情变化的研究分析。

Objective The aim of this study was to establish an acute gastric mucosal injury(AGMI)rat model induced by hydrochloric acid(HCl)at different concentration gradients and to investigate the effects of intravenous injection of evans blue(EB)at various concentrations and dosages on survival rate and superficial extravasation.Methods(1)Wistar rats were randomly assigned to five weight-based groups:150~180 g,180~200 g,200~250 g,300~400 g,400~500 g.Each group was further subdivided into eight subgroups based on HCl concentration,specifically:0.40,0.45,0.50,0.55,0.60,0.65,0.70 mol/L HCl,along with a control group treated with saline.This result ed in a total of 40 subgroups,with three rats per subgroup,summing up to 120 animals in total.The survival rate of rats 24 hours post-modeling was assessed,and the interaction between body weight and HCl concentration on rat survival was analyzed.Following the establishment of five graded HCl concentrations,gastric mucosal pathological changes were observed microscopically using hematoxylin-eosin staining(HE)staining.(2)From these result,the highest suitable concentration of HCl was selected to prepare the AGMI model.Subsequently,rats were randomly allocated into different groups based on the concentration and dose of EB,specifically:EB 1(0.5%,0.4 mL),EB 2(1%,0.1 mL/100 g),EB 3(1%,0.2 mL/100 g),EB 4(2%,0.1 mL/100 g),EB 5(2%,0.2 mL/100 g),and EB 6(5%,0.1 mL).Each group consisted of five rats,totaling 30 animals.The survival rate and extent of dermal exudation were evaluated 24 hours post-injection of EB.Results(1)Post-modeling symptoms in AGMI rats intensified with increasing concentrations of HCl,with the 24-hour survival rate in all weight groups being 0%for both 0.65 mol/L and 0.70 mol/L HCl.Kaplan-Meier survival curves indicated significant differences in survival rates among rats in different HCl concentration groups(P<0.001).Furthermore,a significant interaction effect between HCl concentration and body weight on rat survival time was observed(P<0.001).The five gradient HCl concentrations established were from 0.40、0.45、0.50、0.55、0.60 mol/L.Histological observations revealed that the degree of inflammatory cell infiltration in the gastric mucosa of AGMI rats escalated with increasing HCl concentrations.(2)AGMI rats prepared with 0.60 mol/L HCl and injected with 5%EB(0.1 mL)had a 24 h survival rate of only 40%.Kaplan-Meier survival curves showed no significant differences in survival rates among AGMI rats under different concentrations and dosages of EB(P>0.05).Analysis of superficial extravasation revealed that skin and eye color were lighter in EB 1 group rats,with fewer extravasation points,while rats in EB 4 and EB 5 groups exhibited more apparent skin color changes and extravasation.One-way ANOVA further confirmed that the number of superficial EB extravasation points in the EB 3,EB 4,and EB 5 groups was significantly higher than that in EB 1 group(P<0.05,P<0.01).Conclusions HCl modeling successfully achieved a setting of multiple precise concentration gradients.Gastric lavage with HCl concentrations ranging from 0.40 mol/L to 0.60 mol/L in rats with a fasting body weight of 180~200 g was used to successfully prepare an AGMI model.Intravenous injection of 2%EB(0.2 mL/100 g)can facilitate the study and analysis of the distribution characteristics of superficial EB extravasation points in AGMI rats over time and as the condition progresses.