The permeability of glomerular basement membrane (GBM) was assessed in vitro by the filtration of solutions of proteins across films formed from isolated pig GBM. Incubation of the films with fructose or glucose increased their permeability to water and serum albumin. The effect of fructose was similar to that previously noted for films crosslinked with glutaraldehyde. The metal chelator DTPA abolished the effects of glycation; EDTA was partially effective in this respect. Transition metal catalysed formation of glycoxidation induced crosslinks may explain the increased permeability of glycated GBM.
