西咪替丁对坏死性小肠结肠炎新生大鼠CaMKIV/CREM通路及肠上皮完整性的影响  

The effects of cimetidine on the calmodulin-dependent protein kinase IV/cyclic AMP response element modulator pathway and intestinal epithelial integrity in necrotizing enterocolitis in neonatal rats

作　　者：孙子梅[1] 林晓燕[1] 苏琴 毕胜利[1] SUN Zimei;LIN Xiaoyan;SU Qin;BI Shengli(Department of Paediatrics,the Second Affiliated Hospital of Hebei North University,Zhangjiakou 075100,China)

机构地区：[1]河北北方学院附属第二医院儿科,河北张家口075100

出　　处：《中国比较医学杂志》2021年第3期49-54,共6页Chinese Journal of Comparative Medicine

基　　金：河北省科技计划项目(122777135)。

摘　　要：目的探讨西咪替丁对坏死性小肠结肠炎(NEC)肠上皮完整性及钙调蛋白依赖性蛋白激酶IV(Ca MKIV)/环磷酸腺苷反应元件调节蛋白(CREM)通路的影响。方法实验分为对照组、模型组、西咪替丁组和Ca MKIV抑制剂组。除对照组外,其余各组出生1 d缺氧+复氧+冷刺激建立NEC新生大鼠模型,连续3 d。每天刺激后西咪替丁组静脉注射30.5 mg/kg西咪替丁,Ca MKIV抑制剂组插管灌胃0.72 mg/kg Ca MKIV抑制剂KN62,对照组和模型组静脉注射和灌胃生理盐水处理相同天数。观察大鼠临床情况;异硫氰酸荧光素-葡聚糖(FITCDextran)示踪法检测肠道通透性;苏木精-伊红(HE)染色观察肠道组织病理学变化;酶联免疫吸附(ELISA)检测大鼠肠组织中血小板活化因子(PAF)、肿瘤坏死因子α(TNF-α)水平;蛋白免疫印迹检测大鼠肠组织中Ca MKIV、CREM蛋白水平。结果模型组出现活动减少、反应迟钝现象,喂养时出现不耐受现象,大便形状改变;肠壁充气扩张、弹性差,部分出现穿孔现象,显微镜下观察到黏膜下层或固有层分离严重,绒毛脱落、腺体紊乱。西咪替丁组和Ca MKIV抑制剂组较模型组活动量有所增加,喂养状态缓和;肠壁充气扩张,显微镜下观察黏膜下层或固有层部分分离,出现部分绒毛脱落现象。与对照组相比,模型组肠道FITC-Dextran水平,组织学评分,肠组织中PAF、TNF-α水平,Ca MKIV、CREM蛋白水平升高(P <0.05);与模型组相比,西咪替丁组、Ca MKIV抑制剂组肠道FITCDextran水平,组织学评分,肠组织中PAF、TNF-α水平,Ca MKIV、CREM蛋白水平降低(P<0.05)。结论西咪替丁可能通过抑制Ca MKIV/CREM通路缓解NEC中炎症进而改善肠上皮,从而实现对NEC新生大鼠的保护。Objective To investigate the effect of cimetidine on intestinal epithelial integrity and the calmodulindependent protein kinase IV(Ca MKIV)/cyclic AMP(c AMP)response element modulator(CREM)pathway in necrotizing enterocolitis(NEC).Methods Rats were divided into a control group,model group,cimetidine group,and Ca MKIV inhibitor group.Except for the control group,the NEC newborn rat model was established by hypoxia+reoxygenation+cold stimulation on the first day of birth in each group over 3 consecutive days.After daily cold stimulation,30.5 mg/kg cimetidine was injected intravenously in the cimetidine group.In the Ca MKIV inhibitor group,0.72 mg/kg of the Ca MKIV inhibitor,kn62,was administered by intubation,and the control group and model group were treated with normal saline for the same number of days.The rats were then observed clinically.Intestinal permeability was measured by the fluorescein isothiocyanate-dextran(FITC-dextran)tracing method;hematoxylin eosin(HE)staining was used to observe the histopathological changes of the intestinal tract;the concentrations of platelet activating factor(PAF)and tumor necrosis factor-α(TNF-α)were detected by enzyme-linked immunosorbent assay(ELISA);and the protein levels of Ca MKIV and CREM were detected by Western blot.Results In the model group,we observed decreased activity and slow responses,low appetite,and change of stool shape.The intestinal wall was thickened and edematous,with poor elasticity and some perforation,microscopically;the submucosa or lamina propria were markedly separated;villi were missing;and glands were disordered.Compared with the activity in the model group,activity in the cimetidine group and Ca MKIV inhibitor group increased,and appetite was moderate;the intestinal wall was thickened and edematous,microscopically;and the submucosa or lamina propria were partially separated,with some partially denuded villi.Compared with the control group,the FITC-dextran levels,histological scores,and the levels of PAF,TNF-α,Ca MKIV,and CREM proteins in the

关 键 词：西咪替丁 坏死性小肠结肠炎 新生大鼠 肠上皮完整性 钙调蛋白依赖性蛋白激酶IV/环磷酸腺苷反应元件调节蛋白通路 

分 类 号：R-33[医药卫生]