EVIDENCE FOR THE MAILLARD REACTION IN RAT LUNG COLLAGEN AND ITS RELATIONSHIP WITH SOLUBILITY AND AGE

This study investigated age-related changes in collagen solubility and collagen-linked fluorescence, and their relationship with the Maillar d reaction. As a result of the collagen purification of rat lung sampl es, we obtained two pools of collagen with different degrees of solubi lity. The relative distribution of collagen between these two fraction s was time-dependent, and the proportion of the smaller and less solub le fraction increased with time (r = 0.73, P < 0.0001). In this fracti on, the intensity of fluorescence at Exc 335 nm/Em 385 nm, and the tot al amount of pentosidine increased with age (r = 0.66, P < 0.002, and r = 0.69, P < 0.01, respectively). The mean values for fluorescence an d pentosidine per milligram of collagen were, respectively, six and te n times greater in the less soluble fraction. In this fraction the pen tosidine per milligram of collagen increased with age (r = 0.59, P < 0 .03). Our results demonstrated the presence of pentosidine in rat lung collagen. Moreover, its accumulation in the less soluble fraction sug gested a relationship between Maillard reaction products, physico-chem ical changes in collagen solubility, and the ageing process in rat lun gs.