URINARY PYRRALINE AS A BIOCHEMICAL MARKER OF NONOXIDATIVE MAILLARD REACTIONS IN-VIVO

The presence of pyrraline, a non-oxidative glucose-derived Maillard re action product in plasma proteins has been established previously. In this study we have investigated the presence of pyrraline in human uri ne to determine whether pyrraline-containing proteins are metabolized or selectively retained. Pyrraline was detected by means of HPLC, and its presence was confirmed by UV and electrospray-mass spectrometry. T he quantification of pyrraline in urine from healthy individuals showe d 1.21+/-0.4 mu g/mg creatinine. In urine from diabetic patients, pyrr aline levels varied considerably, although the mean level was higher t han in healthy subjects (1.37+/-0.6 mu g/mg creatinine). These data fu rther support the presence of a catabolic pathway for advanced non-oxi dative Maillard reaction products in vivo and suggest their role in th e pathogenesis of diabetes.