High fat diet induced fluorescence and increased resistance of collagen to proteolytic cleavage

Feeding of animals with high fat diets results in a distinct increase in the stability of the collagen structure as reflected by its higher resistance towards proteolytic cleavage. It appears that covalent cross links are formed when the experimental animals are fed a diet containing a high proportion of unsaturated fatty acids, i.e. when the chance of the formation of reactive intermediates is increased. This is based on the observation of the presence of non-reducible high molecular weight collagenous material in pepsin treated collagen. This high molecular weight fraction exhibited a typical 390/460 nm fluorescence and a distinct decrease of lysine content. It is suggested that the observed phenomena result from the action of in vivo present potential cross-linking agents.