Increased glycoxidation and lipoperoxidation in the collagen of the myocardium in hemodialysis patients.

Objective: The purpose of this study was to examine the glycoxidation and lipoperoxidation products in the collagen of the myocardium in hemodialysis (HD) patients and age-matched control subjects.

Methods: Cardiac samples from 15 autopsied subjects (HD, n=6; control, n=9) were sequentially extracted with 0.9% NaCl and collagenase to obtain two fractions [soluble fraction (SF) and collagenase soluble fraction (CSF)]. The glycoxidation and lipoperoxidation products of these two fractions were measured by pentosidine-linked fluorescence (lambda(ex), 335; lambda(em), 385) and malondialdehyde (MDA)-linked fluorescence (lambda(ex), 390; lambda(em), 460), respectively.

Results: Both pentosidine- and MDA-linked fluorescence were found to have significantly increased more in the collagenase soluble fraction (CSF) extracted form the anterior and posterior wall in HD patients than in the controls (P<0. 05, control, n=9 vs. HD, n=6). Interestingly, the level of the lipid peroxides strongly correlated with that of the glycoxidation product in CSF (both P<0.0001 for the anterior and posterior wall). In contrast, in SF, which did not contain matrix collagen, neither significant difference nor correlation in the levels of pentosidine- and MDA-linked fluorescence was observed in these two groups.

Conclusion: the present study provides the first biochemical evidence for an increase in glycoxidation and a close link between glycoxidation and lipoperoxidation in the collagen of the myocardium in hemodialysis patients. These findings suggest that these two spontaneous chemical reactions in the collagen matrix of myocardium may synergistically contribute to cardiac damage in hemodialysis patients.