Influence of chain length of N-acetyl-D-glucosamine and D-glucosamine residues on direct and complement-mediated chemotactic activities for canine polymorphonuclear cells

The direct and complement-mediated chemotactic activities (CA) of N-acetyl-D-glucosamine (GlcNAc), D-glucosamine (GlcN), GlcNAc and GlcN oligomers, chitin and chitosan for canine polymorphonuclear cells (PMNs) were investigated in vitro. GlcNAc6 and GlcN5 similar to 6 provided the most effective stimulation of CA, with GlcN6 having a seven-fold stronger effect than GlcNAc6. Serum incubated with chitin and chitosan (37 degrees C, 30min) had a similar CA to that of zymosan. The total complement activity (CH50) of serum mixed with chitin and chitosan was lower than control level, but monomers and oligomers of GlcNAc or GlcN did not decrease complement activity. Subcutaneous injection of GlcN6 and chitosan enhanced more PMN migration than GlcNAc6 and chitin in vivo. It was demonstrated that GlcN residues induced higher direct CA than GlcNAc residues, while complement-mediated CA was only induced by chitin and chitosan, but not by GlcNAc, GlcN and their oligomers. (C) 1997 Elsevier Science Ltd.