Studies on pharmacological activation of human serum immunoglobulin G by chemical modification and active subfragments. IX. Anti-inflammatory activity of completely alkylated heavy chain (C.Fr.I-H).

The anti-inflammatory activity of completely reduced and carboxamide-methylated heavy chain of all disulfide bonds in human serum immunoglobulin G (IgG) (C.Fr.I-H) was investigated using some experimental inflammatory models. C.Fr.I-H significantly inhibited carrageenin-induced paw edema and pleurisy, and serotonin-induced paw edema. The carboxamide-methylated heavy chain of interchain disulfide bonds in IgG (Fr.I-H) exhibited similar inhibitory activities to C.Fr.I-H on carrageenin-induced paw edema and pleurisy, while it was ineffective on serotonin-induced paw edema. These results suggest that complete alkylation of disulfide bonds in a heavy chain caused stronger anti-inflammatory activities than partial alkylation.