A quantitative method for assessing the extent of experimental gastric erosions and ulcers

Evaluation of acute gastric erosions and ulcers induced by chemicals such as ethanol or aspirin is difficult because these lesions are predominantly multiple and irregularly shaped. A commercially available, relatively inexpensive microprocessor-linked planimeter (Micro-Plan II) with a stereomicroscope was used to measure the area of gastric mucosa damaged following intragastric administration of various doses of ethanol or aspirin. An enlarged image of rat glandular stomach was projected from the stereomicroscope onto a planimeter on which the perimeter of the entire glandular stomach and each lesion was traced with an electronic cursor. An attached printer recorded the area of stomach assessed, the number of lesions, the surface area of each lesion and the total area of mucosal damage. The technique was compared with semiquantitative methods used previously to assess experimentally induced gastric mucosal damage. The quantitative morphometric method was sufficiently sensitive to demonstrate a dose-response effect of ethanol and aspirin. The stereomicroscope--planimeter combination provides a sensitive method to quantitate either a few small, or numerous large, regularly or irregularly shaped hemorrhagic and nonhemorrhagic gastric mucosal lesions.