1、causes,aggressive factors defensive factors ,peptic ulcer occur,Aggressive Factors,3.Gastric acid and pepsin(胃酸与胃蛋白酶),2. Adverse effects of drugs,such as NSAID,1. Helicobacter pylori infection(幽门螺杆菌感染),4.others,1.Helicobacter pylori (H.p),the evidences . the detection rate of H.p in GU is approximat
2、ely70% -80% . the detection rate of H.p in DU is approximately 90% . Eradication of H.p would boost the healing of ulcer.How can H.p destroy local mucosal defective/repaired mechanism? 1. colonize the gastric mucosa（胃粘膜）. 2. increased acid secretion,2.NSAID,After H.p infection, NSAID is the next imp
3、ortant cause . Research data show that NSAID use in patients with peptic ulcer and the risk of complications was significantly higher than the general population. By weakening mucosal defense and repair functions eventually lead to peptic ulcer.,案例展示,3.Acid and pepsin,The eventual formation of pepti
4、c ulcer is due to acid and pepsin digestion of the mucosa itself. Because the biologic activity of pepsin is depended on the pH value. When local pH value elevates to 4, pepsin cant work well. So we often say that “No acid, no ulcer.”,4. Other risk factors,1) Smoking Smoking is an increased risk of
5、peptic ulcer. Smoking can affect the healing of ulcer, accelerate ulcer recurrence, and increased complication of ulceration. But the mechanism isnt clear.,2)Heredity Patients with peptic ulcer often have a family history of ulcer.And some studies show that blood group O（O型血人群） have a high risk to d
6、eveloping peptic ulcer .,3)Stress High stress can stimulate vagus nerve(交感神经), which can result in high secretion of acid .,4) Abnormal gastroduodenal locomotion胃十二指肠功能异常DUquick gastric empty overfull acid load food storageGUmovement obstructionreflux digestive liquid 阻滞,1.High acid secretion 2.Aggr
7、avating H.p infection 3.Increased bad effect of NSAID,Defensive Factors,2.Mucosa Barrier（粘膜屏障）,1.Mucus/Bicarbonate Barrier（粘液、碳酸氢盐屏障）,3.Mucosal Blood Flux（胃粘膜血流屏障）,4.Others,1.Mucus/Bicarbonate Barrier,The first line of defense is mucus and bicarbonate secretion(粘液和碳酸氢盐的分泌). It stabilizes the pH betw
8、een the lumen and the surface epithelial cells. Mucus gel( 粘液凝胶)in patients with H.p infection was found to be structurally weak.,2.Mucosa Barrier,The second line of defense is the intrinsic epithelial cell defense（上皮细胞防御、粘膜屏障） The mucosal surface is a barrier to acid back diffusion thus maintaining
9、 normal intracellular（细胞内） pH.,3.Mucosal Blood Flux,The third line of defense is the rich mucosal blood flow(丰富的粘膜血流屏障). The blood provides a buffer for acid neutralization（中和） as well as adequate nutrition for the metabolic（代谢） demand to maintain mucosal integrity.,4.Others,Prostaglandin(前列腺素), can reduce the secretion of acid.Feedback regulation of gastric secretion.（胃的分泌的反馈调节）,conclusion,when the balance between aggressive factors anddefensive factors was brokend , peptic ulcers would occur.,
