ISSN:
1432-0428
Keywords:
d-Lysine
;
Maillard reaction
;
non-enzymatic glycation
;
proteins
;
diabetes mellitus
;
streptozotocin rat model
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary d-Lysine, the non-physiological isomer of l-lysine, can competitively reduce protein non-enzymatic glycation in vitro. To study the effect of d-lysine in vivo, 6–8-week old Sprague-Dawley rats with streptozotocin-induced diabetes mellitus were treated from diagnosis for 45 days with two daily subcutaneous injections of d-lysine (0.5 g·ml−1·day−1). Another group of diabetic rats was only injected with equal volumes of physiological saline (0.9% NaCl). Glycated haemoglobin was measured by ion exchange chromatography, and glycated serum and lens proteins by boronate affinity gel chromatography. Serum and urinary creatinine concentrations were evaluated by the alkaline-picrate reaction. Urinary lysine concentrations at mid- and end-study were evaluated by cation exchange chromatography. Blood glucose concentrations, serum creatinine levels and creatinine clearances, measured at the end of the study, were similar in both diabetic groups (〉 22.0 mmol/l, ≤ 106 μmol/l and ≈ 0.02 ml/s, respectively). Urinary lysine concentration in d-lysine-treated diabetic animals was more than 50-fold higher than in placebo-treated diabetic rats. In d-lysine-treated vs placebo-treated diabetic animals, a statistically significant reduction was found in the levels of glycated haemoglobin (stable HbA1; mean ± SD=3.00±0.74% vs 4.02±0.46%, p〈0.05; labile HbA1=3.92±0.89% vs 5.84±0.61%, p〈0.005), glycated serum proteins (1.40±0.47% vs 2.52±1.15%, p〈0.05) and glycated lens proteins (4.90±0.96% vs 5.98±0.65 %,p〈0.05). Thus, d-lysine (i) is not nephrotoxic and (ii) causes a significant reduction of the early glycation products at the protein level. Therefore, the d-amino acid could be useful in attempting to control damaging phenomena associated with or due to an enhanced protein non-enzymatic glycation.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00400352
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