SUBCUTANEOUS INJECTED CHITOSAN INDUCES SYSTEMIC ACTIVATION IN DOGS

Systemic activation by subcutaneous administration of chitin, chitosan , and chitosan oligomer was investigated in dogs by determining the ch emiluminescence (CL) response of circulating polymorphonuclear cells ( PMN). Chitin (10 and 100 mg/kg), chitosan oligomer (10 mg/kg), latex b eads (10 mg/kg) and physiological saline (10 ml) did not cause activat ion of PMN. However, chitosan caused systemic activation of PMN in a d ose-dependent manner. The peak CL response of PMN was significantly in creased in the 1 and 10 mg/kg chitosan groups at 3 days after administ ration. In addition, chitosan (10 mg/kg) prevented a decrease of the C L response in dogs given dexamethasone. Serum obtained from the 10 mg/ kg chitosan group significantly activated PMN from normal dogs. At 3 d ays after chitosan administration, the serum level of complement compo nent 3 (C3) was increased about 1.6 times that of the prechitosan C3 l evel. In conclusion, subcutaneous administration of chitosan induces s ystemic activation of both PMN and serum. Copyright (C) 1997 Elsevier Science Ltd. All rights reserved.