Increased capillary permeability in guinea pigs and rats by peptidoglycan fraction extracted from Group A streptococcal cell walls.

The increased capillary permeability in the skin of guinea pigs and rats was induced by peptidoglycan fraction (PG fraction) extracted from cell walls of group A streptococcus, but not by C-carbohydrate of streptococcal cell walls nor lipopolysaccharide of Escherichia coli and Salmonella abortus. The increased capillary permeability caused by PG fraction was also observed in germ-free rats. It was suggested that the increased capillary permeability for PG fraction might be due to the biological activity of PG fraction. The pattern of the reaction of increased capillary permeability consists of two phases: the leakage of the dye in the first phase appeared immediately after the intracutaneous injection of PG fraction, and the second phase seems to depend upon vasculitis. The increasing activity of capillary permeability to PG fraction may play an important role in inducing initial change of tissue injury by streptococcal cell walls.