L-arginine reduces kidney lipid peroxidation, glycoxidation and collagen accumulation in the aging NMRI mouse.
Collagen accumulation in organs is a main feature of the physiological aging process. There are two main theories for the responsible mechanisms, the free oxygen radical and the glycoxidation theory. Both lead to carbonyle-induced protein modification, increased collagen cross-linking and subsequently to the collagen accumulation. In previous studies we provided evidence for the blocking of reactive carbonyles by L-arginine in the diabetic state and present here data for this effect in the aging NMRI mouse. NMRI mice were fed L-arginine in tap water for a period of 6 months and compared to an untreated control group. Kidney collagen content of the treated group was significantly reduced (treated: 8.83 +/- 0.72 mg collagen/100 mg kidney weight; untreated: 11.95 +/- 0.98 mg collagen (100 mg kidney weight; p < 0.05). Using a colorimetric assay for lipid peroxidation products we found significantly reduced lipid peroxidation-derived aldehydes in the treated group (treated: 0.25 +/- 0.03 extinction; untreated: 0.36 +/- 0.04 extinction; p < 0.05). The parameter for glycoxidation, N-epsilon-carboxymethyllysine (CML) was significantly lower in the experimental group as well (treated: 2.3 +/- 0.5 nM CML/microM hydroxyproline; untreated: 4.3 +/- 0.52 nM CML/microM hydroxyproline; p < 0.05). No differences were observed for the biomarker of hydroxyradical attack, o-tyrosine. L-Arginine could have reduced collagen accumulation by blocking collagen glyc(oxidation) which is known to lead to increased collagen cross-linking, solubility and degradation as a strong correlation between both CML and collagen content (r2 = 0.654, p < 0.05) as well as between lipid peroxidation products and collagen content (r2 = 0.539, p < 0.05) was observed.
Lubec
B
B
Department of Paediatrics, University of Vienna, Austria.
Golej
J
J
Marx
M
M
Weninger
M
M
Hoeger
H
H
D000375:Aging; D000818:Animals; D001120:Arginine / Q000378:metabolism / Q000494:pharmacology*; D003094:Collagen / Q000378:metabolism*; D003864:Depression, Chemical; D005260:Female; D005920:Glomerular Mesangium / Q000502:physiology; D007668:Kidney / Q000033:anatomy & histology / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects; D008239:Lysine / Q000031:analogs & derivatives* / Q000378:metabolism; D051379:Mice; D008815:Mice, Inbred Strains; D009929:Organ Size; D014443:Tyrosine / Q000378:metabolism
D014443:Tyrosine; C026741:2-tyrosine; C048496:N(6)-carboxymethyllysine; D003094:Collagen; D001120:Arginine; D008239:Lysine