PROTEIN GLYCATION AND FLUORESCENT MATERIAL IN HUMAN ATHEROMA

Samples of normal human aorta, atherosclerotic lesions and atheroma (n ecrotic ''gruel'' from the interior of advanced lesions) were obtained at necropsy from subjects with no history of diabetes mellitus. Compo nents of each were extracted by ethanol:diethylether (3:1) and, subseq uently, by 10% sodium dodecyl sulphate (SDS). Both fractions, organic and aqueous (SDS), were assessed for their relative fluorescence (exci tation: 350 nm/emission: 430 nm). The amount of early products of glyc ated protein was assessed by affinity chromatography in the SDS-solubl e fraction. Age-matched plasma samples, obtained from non-diabetic ind ividuals, were also examined. Material from atherosclerotic lesions ap peared to exhibit an inverse correlation between protein glycation and fluorescent material which was best reflected within the organic extr act. This was not the case for normal aorta. A linear correlation betw een fluorescent material in the organic extract and SDS extract existe d in the normal aorta alone. The only ape-dependent change was found i n normal aorta in which there was an increase in SDS-soluble fluoresce nce with increasing age. In plasma samples alone, protein glycation an d protein fluorescence appeared to be linearly correlated. The observa tions are discussed in the context of the possible contribution of pro tein glycation to atherogenesis.