Permeability factor and kininogenase in guinea-pig serum fractions.

Several protein fractions of guinea-pig serum that were separated by the aqueous ether method, were assayed for permeability-increasing activity in the skin of guinea-pigs having a circulating blue dye. The fractions were also examined for kininase and kininogenase activity. Kininase was found consistently associated with the α and β globulins, both in fractions that had strong permeability-increasing activity and in fractions that contained the inhibitor (IPF) of permeability factor. Weak kininogenase activity was found only in fractions of strong permeability-increasing activity, and it was removed by heating without substantially affecting the permeability-increasing activity. The results do not support the view that kininogenase activity is responsible for the major permeability-increasing activity of guinea-pig serum fractions prepared by the aqueous ether method.