STUDIES ON GASTRIC-MUCOSAL MICROCIRCULATION .1. THE NATURE OF REGIONAL VARIATIONS INDUCED BY ETHANOL INJURY

Background/Aims-The focal nature of gastric ulcers raises the possibil ity of underlying regional disturbances in gastric mucosal microcircul ation. This study employed fluorescent in vivo microscopy with the aim of directly investigating the response of several areas of the gastri c mucosa to 60% ethanol. Methods-Changes in macromolecular leakage of fluorescein labelled albumin, vessel diameter, and acridine red labell ed leucocyte adhesion and rolling were assessed over a period of two h ours. A total of 0.5 ml 60% ethanol was topically applied for five min utes to the exteriorised gastric mucosa of anaesthetised rats. Rats-Th ree distinct patterns of response were found. Areas of lesion formatio n were small and occurred within five minutes. These areas showed pers istent blood flow stasis throughout the course of the experiment, incr eased leakage (p<0.02), and no leucocyte adhesion. Peripheral to the l esion, sustained leakage (p<0.02) was found with adherence of leucocyt es (p<0.01) after lesion formation. Sites more remote to any lesion sh owed transient leakage and significant numbers of 'rolling' leucocytes (p<0.01) were observed again after the lesion had formed. Conclusions -Despite widespread exposure of the entire gastric mucosa to 60% ethan ol the resultant mucosal injury was limited. Widespread vascular damag e was found reflected by macromolecular leakage, the pattern of which showed regional variation.