Isolation of substances with vascular permeability-increasing activity from the skin of the plaice (Pleuronectes platessa L.)

A methanolic extract of plaice skin, from which lipids had been removed, was chromatographed on alumina, eluted with decreasing concentrations of ethanol. Only the 60% ethanol fraction exhibited smooth muscle activity, with bradykinin-like properties. The 20% ethanol fraction increased vascular permeability in rat skin, as measured by dye-leakage. This was not due to the degranulation of mast cells. Intradermal injection of either fraction into the plaice caused localized erythema.