SERUM LEVELS OF 3-DEOXYGLUCOSONE AND TISSUE CONTENTS OF ADVANCED GLYCATION END-PRODUCTS ARE INCREASED IN STREPTOZOTOCIN-INDUCED DIABETIC RATS WITH NEPHROPATHY

To investigate a role of the Maillard reaction in the pathogenesis of diabetic nephropathy, we measured serum levels of 3-deoxyglucosone (3- DG), a potent protein cross-linking intermediate of the Maillard react ion, and tissue contents of advanced glycation end products (AGEs) in streptozotocin (STZ)-induced diabetic rats. We quantified serum 3-DG u sing gas chromatography/mass spectrometry, and measured AGE contents i n tissues using a competitive enzyme-linked immunosorbent assay with a monoclonal anti-AGE antibody. The STZ-induced diabetic rats showed ne phropathy with proteinuria, hypoproteinemia, hyperlipidemia and reduce d creatinine clearance. Serum levels of 3-DG in the STZ-induced diabet ic rats (mean +/- SE; 3.46 +/- 0.23 mu mol/l) were significantly (p < 0.01) higher than those in control rats (1.23 +/- 0.13 mu mol/l). AGE contents in the kidney and the lens obtained from the STZ-induced diab etic rats(398 +/- 45 and 816 +/- 200 arbitrary units, respectively) we re also significantly (p < 0.01) higher than those in the control rats (122 +/- 10 and 299 +/- 50 arbitrary units, respectively). The result s indicate that increased levels of serum 3-DG and renal tissue AGEs m ay be related to the occurrence of diabetic nephropathy.