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 chemiluminescence (CL) response of circulating polymorphonuclear cells (PMN). Chitin (10 and 100 mg/kg), chitosan oligomer (10 mg/kg), latex beads (10 mg/kg) and physiological saline (10 ml) did not cause activation of PMN. However, chitosan caused systemic activation of PMN in a dose-dependent manner. The peak CL response of PMN was significantly increased in the 1 and 10 mg/kg chitosan groups at 3 days after administration. In addition, chitosan (10 mg/kg) prevented a decrease of the CL response in dogs given dexamethasone. Serum obtained from the 10 mg/kg chitosan group significantly activated PMN from normal dogs. At 3 days after chitosan administration, the serum level of complement component 3 (C3) was increased about 1.6 times that of the prechitosan C3 level. In conclusion, subcutaneous administration of chitosan induces systemic activation of both PMN and serum. Copyright (C) 1997 Elsevier Science Ltd. All rights reserved.