title: Reversal by aminoguanidine of the age-related increase in glycoxidation and lipoxidation in the cardiovascular system of Fischer 344 rats.
abstract: Non-enzymatic glycoxydation and lipoxidation of proteins continues to stimulate great interest in gerontology as both markers and promoters of aging. The first aim of the study was to determine the age-related changes in levels of Nepsilon-(carboxymethyl)lysine (CML) and 4-hydroxy-2-nonenal (HNE) present on proteins of the cardiovascular system of Fischer 344 rats and identify the particular polypeptides being modified. The second objective was to evaluate whether pharmacological administration of aminoguanidine (1g/L in the drinking water) could reverse protein glycoxidation and lipoxidation. CML content in serum, aorta, and heart proteins from 28-month-old rats was double of that found in 4-month-old animals. AG administration to old rats for 3 months from the age of 25 months lowered CML content by 15 (P=.2275), 44 (P<.0001), and 28% (P=.0072) in serum, aorta, and heart, respectively. Serum albumin, transferrin and immunoglobulins were most prominently adducted by both CML and HNE. While the extent of albumin and transferrin modification was comparable between age groups, CML and HNE bound to immunoglobulins increased in the sera of old rats as a result of the accumulation of immunoglobulin heavy and light chains. AG treatment prevented immunoglobulin accumulation in serum, suggesting a beneficial action on renal filtration. Lipoxidation of heart mitochondrial proteins was prevalent over glycoxidation, either as CML or pentosidine. Although AG prevented HNE-induced inactivation of the alpha-ketoglutarate dehydrogenase complex in vitro, it had no effect in rat hearts, suggesting AG could not reach the mitochondrial matrix.
authors.affiliation: Linus Pauling Institute, Oregon State University, Corvallis, OR 97331-6512, USA. regis.moreau@oregonstate.edu
authors.forename: Régis
authors.initials: R
authors.lastname: Moreau
authors.forename: Binh T
authors.initials: BT
authors.lastname: Nguyen
authors.forename: Catalin E
authors.initials: CE
authors.lastname: Doneanu
authors.forename: Tory M
authors.initials: TM
authors.lastname: Hagen
mesh_terms: D000375:Aging / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence / Q000235:genetics; D000818:Animals; D002319:Cardiovascular System / Q000187:drug effects* / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006146:Guanidines / Q000494:pharmacology*; D015227:Lipid Peroxidation / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D006146:Guanidines; D005947:Glucose; C004479:pimagedine