Association of Granulocytes With Ulcer Formation in the Stomach of Rodents Exposed to Restraint Stress

Increased levels of granulocytes in the blood were first estimated in patients with gastric ulcer.Then, experiments were extended to rodents, including mice and rats.Restraint stress was induced by fixing rodents in stainless steel mesh.Infiltration of granulocytes and other cells was determined in various organs of mice by using mAbs in conjunction with immunofiuorescence tests.Severe granulocytosis was induced in various organs, including the stomach, blood, and liver 24h after the exposure.Interestingly, extrathymic T cells, which are known to have the ability to kill rapidly proliferating autologous self-cells, increased in parallel.More importantly, the pre-elimination of granulocytes by anti-granulocyte mAb abrogated the formation of ulcers in rats, whereas the preactivation of granulocytes by G-CSF accelerated formation.The present results suggest that the background or basal conditions in hosts may be very critical for the formation of gastric ulcers and the occurrence of other damage to organs.