Changes in vascular permeability associated with acetic acid-induced gastrin ulcer in rats.

Gastric ulcer was induced in rats by application of acetic acid to the anterior wall of the stomach. Leakage of circulating albumin into the gastric wall was estimated by intravenous injection of radioactive albumin and determination of the radioactivity in different samples of the stomach wall. The protein leakage was found to be markedly increased in the anterior wall of the stomach, the increase being most pronounced close to the ulcer. The leakage remained fairly constant during the first 10 h of the experiment. The protein content of the posterior wall was about the same as in animals on which a sham operation had been performed. The protein leakage was associated with considerable oedema formation. The protein leakage indicates that inflammatory mediators are released in a wide area around the ulcer. The present experimental model offers an opportunity to find out which mediators are involved in the lesion.