Release of neutrophil chemotactic factors from gastric tissue. Initial biochemical characterization

This study was designed to characterize neutrophil chemotactic factors released by gastric tissue. Full-thickness rabbit stomach (organ culture) was prepared and incubated in Ringer's solution at 37 degrees C. Culture supernatants were collected at 1, 2, 3, and 4 hr and assayed for neutrophil chemotactic activity in modified Boyden chambers. High levels of chemotactic activity were seen at 3 hr of incubation. Antral and fundic tissue were equally capable of producing neutrophil chemotactic activity. In addition, high levels of activity were seen from both the serosal and mucosal surfaces. Initial biochemical characterization of these gastric-derived factors revealed that: (1) a majority of the activity (80-90%) exhibited molecular weight values of greater than 300 kDa, (2) the chemotactic activity was heat stable but was partially reduced by treatment with a protease, subtilisin (37% inhibition), and (3) 70-80% of the activity in the supernatants was extracted into organic solvent (ethyl acetate). These factors may prove to be important in recruitment of neutrophils to areas of gastric injury.