Experimentally induced gastric ulcer in the rat MUDr. Michal Jurajda

Objective n To study the influence of H2-receptor antagonist on the development of the peptic ulcers of the stomach in the rats.The peptic ulcers will be induced experimentally by NSAID (cyclo- oxygenase inhibitor).

Physiology n Motor functions of the stomach n Gastric secretion

Physiology n Motor functions of the stomach –storage: reduction of the tone in the muscular wall –mixing and propulsion: constrictor ring leading to the retropulsion –emptying

Physiology n Secretions –parietal cells - HCl, intrinsic factor –chief cells – enzymes (pepsinogen, gastric lipase) –surface cells - mucous, sodium bicarbonate

Mucous neck cell Parietal cell Chief cell

Gastric mucosa surface cells neck cells parietal and chief cells

Hydrochloric acid secretion

Regulation of HCl secretion

Pathology n Gastritis –Acute - stress (Cushing’s ulcer), infection, radiation, corrosives –Chronic A type – autoimmune destruction of the parietal cells, B type – inflammation of the antral mucosa caused by H. pylori

Gastritis - acute

Chronic gastritis A

Chronic gastritis B

Helicobacter pylori

Peptic ulcer n Mucosal defect reaching deeper than muscularis mucosae layer, localized in areas exposed to acid-pepsin secretions.

Pathological anatomy

RTG with barium contrast Gastric ulcer

Duodenal peptic ulcer

Complications of peptic ulcer n Bleeding n Perforation n Penetration n Pyloric channel narrowing

Peptic ulcer ulcer

Bleeding

Perforation and penetration

Perforation – free intraperitoneal air

Ulcerogenic factors n NSAID n Stress n Chronic gastritis type B n A habitual increase of oxyntic glands secretion (increased number, increased sensitivity to k histamine or gastrin. n Zollinger-Ellison syndrom

Pharmacotherapy

H2 receptor antagonists n block histamine receptors 2 type udecrease HCl secretion in the gastric glands

Cyclooxygenase inhibitors n decrease synthesis of prostaglandins uanti-inflammatory effect uanalgetic effect uanti-trombotic effect uThe adverse side effect - the gastric ulcer