ACTIVE OXYGEN SPECIES GENERATION BY CIRCULATING LEUKOCYTES AND GASTRIC SUBMUCOSAL MICROCIRCULATORY DISTURBANCES IN THE EARLY PERIOD AFTER THERMAL-INJURY

The purpose of the present study was to determine the pattern of micro circulatory disturbance to investigate the causes of gastric mucosal b lood flow depression in the early period after thermal injury. Male Wi star rats were anesthetized and a 30% full skin-thickness dorsal burn was inflicted. Active oxygen species (AOS) generated by circulating le ukocytes were measured by chemiluminescence. Contraction of arterioles and venules was observed by intravital microscopy, and rolling or sti cking of leukocytes in venules was counted using fluorescence microsco py. AOS generation by circulating leukocytes was diminished and arteri olar contraction and increases in rolling or sticking leukocytes in ve nules were observed 15 min after thermal injury. Decreased AOS generat ion by circulating leukocytes, contractions of arterioles, and increas ed rolling or sticking of leukocytes in venules was observed in the ea rly period after thermal injury. Arteriolar contraction may explain de creases in mucosal blood now. Moreover, decreased AOS generation by ci rculating leukocytes does not obviate the potential participation of l eukocytes in microcirculatory disturbances, because rolling or stickin g leukocytes were increased significantly 15 min after thermal injury.