Hemorrhagic shock activates mast cells in the rat stomach wall.

The activation of mast cells (MC) and liberation of their mediators can play an essential role in initiating and controlling inflammatory processes in the wall of the gastrointestinal tract (GIT) due to ischemia. The role of MC in changes induced by hemorrhagic shock (HS) remains unknown. Heparin provided by MC seems to inhibit local inflammation and prevent DIC. The aim of this study was to evaluate the morphometric changes and biochemical activity of MC in the stomach wall after 75 minutes of hemorrhagic shock. The MC in mucosal, submucosal, muscular and serosal compartments of the various stomach wall regions were examined in shocked rats and in the control group. Additionally, the contents of glycosaminoglycans (GAG), measured as uronic acids concentration, as well as anticoagulative activity in the stomach wall were assessed. HS resulted in an evident increase in the number of mast cells detected in the stomach mucosa and serosa, in slight alterations in number of MC in the submucosal and muscular layers, a significant increase in size and changes of the shape of the MC. The elevation of the width, area, and circular shape of MC in all layers were noted. No clear and significant differences between various stomach regions in MC numbers and MC sizes could be shown. No reaction of other inflammatory cells at this stage of shock was observed. Highly significant increases in GAG concentration, and anticoagulative activity in the stomach wall due to shock were noted. The morphometric and biochemical data may indicate MC activation, especially in mucosa and serosa. The shock-induced migration of MC settled in the stomach wall seems to be possible. The results suggest an essential role of MC reaction in the stomach wall in the early phase of hemorrhagic shock.