実験的急性胃病変

Experimental Acute Gastric Lesions

　近年ストレス潰瘍をはじめ，種々の急性胃病変に対する関心がたかまり，新たな立場からの研究が行われつつある．これも内視鏡の進歩普及が大きな役割を果しているといえよう．

　今回われわれは，急性胃病変として，①ストレスによる急性胃病変，②各種薬剤による急性胃病変，③胃の血管性変化による急性胃病変，の3つをとりあげ，実験的にも内視鏡を活用することによっていろいろ検討してみたので，その結果を中心に述べてみたい．

　In this paper we present three types of experimentally induced ulcers.

　1. Stress ulcers : We induced stress ulcers in rats, monkeys, and dogs by the restrained water-immersion method and observed their successive gastric mucosal changes with the gastrofiberscope.

　Histologically, these ulcers were hemorrhagic erosions; they appeared two to three hours after stress in the rats and monkeys but 30 hours later in the dogs. Microthrombi were seen at the top of the mucosa and arterioles were cut off at the base of the hemorrhagic erosions. This finding shows a vascular circulatory disturbance. The morphological changes in the adrenal cortex due to stress were a decrease in lipid droplets and an increase in SER. These changes showed the hyperfunction of the organ.

　Bilateral vagotomy, atropine, and tranquilizers significantly reduced the effect of stress on the gastric mucosa. In addition, bilateral adrenolectomy and hexamethonium appeared to prevent gastric mucosal changes.

　Using this data we discussed the hypothetical development of the stress ulcer.

　2. Drug-induced gastric lesions: We tested in the rat stomach the effects of the drug which induce acute gastric lesions in man.

　Aspirin (100 mg/kg) produced a great number of gastric mucosal changes, and the effect of aspirin was strengthened in the presence of predonisolone, but predonisolone alone scarcely affected the rats' gastric mucosa.

　Some anti-diabetic drugs also induced the gastric mucosal changes.

　Glutamine and DV 1006 greatly reduced the incidence of these lesions.

　3. Acute gastric lesions due to vascular circulatory disturbances : We treated four human cases of giant acute gastric ulcers possibly due to vascular circulatory disturbances

　The patients were over 50 years old and showed severe systemic arteriosclerosis.

　In order to induce this type of ulcer in dogs, Gelfoam (10 to 15 mg) was used as embolus and injected into the dogs' left gastric artery. After three days a large acute gastric ulcer resembling that found in the human cases appeared on the anterior wall of the body. Histologically and microangiographically we demonstrated that existing thrombi caused the ulcer. From these results we suggest that if thrombi occur in human arteries and occlude the arterioles, large, acute ulcers may occur.