Gastric mucosal injury in the rat. Role of iron and xanthine oxidase
Recent studies have implicated oxygen free radicals in ischemia-reperfusion injury to the gastric mucosa. The aims of the present study were to test the hypothesis that the enzyme xanthine oxidase is the source of the oxygen radicals in the ischemic stomach and determine the importance of the iron-catalyzed Haber-Weiss reaction in generating the cytotoxic oxygen radicals. Gastric mucosal clearance of /sup 51/Cr-labeled red blood cells was measured during a 30-min control period, a 30-min ischemic period (hemorrhage to 25 mmHg arterial pressure), and a 60-80-min reperfusion period (reinfusion of shed blood). In untreated (control) rats, a dramatic rise (100-fold) in the leakage of /sup 51/Cr-labeled red blood cells into the gastric lumen was observed only during the reperfusion period. After the reperfusion period, gastric mucosal damage was further assessed using gross lesion area and histology. Rats were placed on a sodium tungstate diet (to inactivate xanthine oxidase), or treated with either deferoxamine (an iron chelating agent) or superoxide dismutase (a superoxide scavenger). All three interventions substantially reduced /sup 51/Cr-labeled red blood cell clearance and gross lesion area relative to untreated rats. However, tissue injury assessed histologically was similar in both treated and untreated animals. The results of this study support the hypothesis that oxygen free radicals mediate the hemorrhagic shock-induced extravasation of red blood cells. The data also indicate that xanthine oxidase is the source of the oxy-radicals and that the iron-catalyzed Haber-Weiss reaction is largely responsible for hydroxyl radical generation in this model.
- Research Organization:
- Univ. of South Alabama, Mobile
- OSTI ID:
- 6520786
- Journal Information:
- Gastroenterology; (United States), Vol. 4
- Country of Publication:
- United States
- Language:
- English
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IRON COMPOUNDS
BIOCHEMICAL REACTION KINETICS
ISCHEMIA
PATHOLOGY
OXIDOREDUCTASES
CHROMIUM 51
DEFEROXAMINE
ERYTHROCYTES
HEMORRHAGE
HYDROXYL RADICALS
MUCOUS MEMBRANES
RATS
STOMACH
SUPEROXIDE DISMUTASE
SUPEROXIDE RADICALS
TRACER TECHNIQUES
TUNGSTEN
AMINES
ANIMALS
BETA DECAY RADIOISOTOPES
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY
BODY FLUIDS
CARDIOVASCULAR DISEASES
CHELATING AGENTS
CHROMIUM ISOTOPES
DIGESTIVE SYSTEM
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
ENZYMES
EVEN-ODD NUCLEI
GASTROINTESTINAL TRACT
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
MAMMALS
MATERIALS
MEMBRANES
METALS
NUCLEI
ORGANIC COMPOUNDS
ORGANS
PATHOLOGICAL CHANGES
RADICALS
RADIOISOTOPES
REACTION KINETICS
RODENTS
SYMPTOMS
TRANSITION ELEMENT COMPOUNDS
TRANSITION ELEMENTS
VASCULAR DISEASES
VERTEBRATES
550901* - Pathology- Tracer Techniques