Effect of chitosan implantation on activation of canine macrophages and polymorphonuclear cells after surgical stress.

The effect of cotton type chitosan implantation under the skin on the immunological response mediated by macrophages and whole blood was evaluated by chemiluminescence (CL) in dogs. The number of white blood cells was significantly decreased until 120 hr after operation in the control group (p < 0.05), while chitosan implantation increased the number of white blood cells, particularly neutrophils, from 24 to 96 hr after implantation (p < 0.05). The CL response of whole blood in the control group seemed to be reduced at 48 and 96 hr after operation (p < 0.05), but in the chitosan groups it maintained higher activity until 120 hr after implantation (p < 0.05). The macrophage activity measured by CL assay in the control group was markedly decreased from 24 to 120 hr after operation, and that for the 5 mg/kg chitosan group was also decreased at 24 and 48 hr after implantation (p < 0.05), although high activity was observed from 72 to 120 hr after implantation (p < 0.05). Neither 5 mg/kg nor 10 mg/kg chitosan groups showed any reduction in CL response of macrophages after operation, and the 20 mg/kg chitosan group retained high CL response of macrophages until 120 hr after operation (p < 0.05). These findings suggest that chitosan may be an efficacious and useful immunopotentiator for preventation of immunosuppression after surgery.