Adhesion, random and chemotactic migration, phagocytosis and nitroblue tetrazolium (NBT) dye reduction of peritoneal exudate polymorphonuclear leukocytes (PMN) and macrophages were examined in 110 rabbits with immune complex-mediated colitis and in controls. We may conclude that Arthus-like colitis in rabbits is accompanied by an impairment of adhesion and phagocytosis, and an increase in chemotactic and random migration of both PMN and macrophages. The examined phagocytes were obtained from the peritoneal cavity, and the changes in their function are related much more directly to the presence of circulating immune complexes than to the colitis. The mentioned impairment in their function may be responsible for prolonged persistence of immune complexes in the serum of rabbits with colitis; however, it does not prolong the time of healing of the ulcers.

Adhesion, phagocytosis, chemotactic and random migration, nitroblue tetrazolium dye reduction of peritoneal exudate neutrophils and macrophages, fibrinogen level, gelation of soluble fibrin and serial dilution protamine sulfate test were investigated in 115 New Zealand white rabbits with experimentally induced Shwartzman phenomenon in the colon, and in control animals. The results presented in this report demonstrated impairment of chemotactic migration of phagocytes in the presence of endotoxin. The depression was dose-dependent and less marked when neutrophils were stimulated with monocyte-derived chemotactic factor or with casein, than with complement-derived chemotactic factor. The prolonged depression of chemotactic migration of neutrophils and macrophages in rabbits with colitis, however, did not affect the healing time of the ulcers in the colon.