title: Dietary restriction of amino acids other than methionine prevents oxidative damage during aging: involvement of telomerase activity and telomere length.
abstract: OBJECTIVE
  It has been suggested that variations in the proportions of some dietary amino acids can slow down aging. In this study, the influence of amino acids other than methionine on aging was investigated.
  
  
  METHODS
  Rats were fed either with normal (ND) or except methionine, protein restricted diet (PREMD) for 4 months and oxygen radical production, oxidative protein and DNA damage along with telomere length and telomerase activity were evaluated in the liver.
  
  
  RESULTS
  Except mitochondrial superoxide production rate, feeding with PREMD significantly decreased the oxygen radical production rate and protein carbonyl levels in the homogenate and mitochondria of 16-month-old rats. Feeding with PREMD prevented 8-OHdG formation in mitochondrial DNA but not in the genomic DNA. Although liver telomerase activities of rats receiving either ND or PREMD seemed to have some variations, these did not reach a statistical significance. Feeding with PREMD conserved the telomere length in the liver. The telomere length of 8- and 16-month-old rats fed PREMD was similar, 16-month-old rats fed ND had telomeres shortened by 36% (p<0.05).
  
  
  CONCLUSIONS
  Long-term restriction of the amino acids other than methionine may decrease oxygen radical generation and oxidative damage of cellular constituents, and may also prevent telomere shortening in rat liver.
authors.affiliation: Istanbul Bilim University Medical Faculty, Department of Biochemistry, Turkey.
authors.forename: Sevda
authors.initials: S
authors.lastname: Tanrikulu-Kucuk
authors.forename: Evin
authors.initials: E
authors.lastname: Ademoglu
mesh_terms: D000080242:8-Hydroxy-2'-Deoxyguanosine; D000375:Aging; D000596:Amino Acids / Q000008:administration & dosage*; D000818:Animals; D004249:DNA Damage / Q000187:drug effects; D004272:DNA, Mitochondrial / Q000187:drug effects / Q000378:metabolism; D003849:Deoxyguanosine / Q000031:analogs & derivatives / Q000378:metabolism; D004044:Dietary Proteins / Q000008:administration & dosage*; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D008715:Methionine / Q000008:administration & dosage; D018384:Oxidative Stress / Q000187:drug effects*; D050050:Protein Carbonylation / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D019098:Telomerase / Q000378:metabolism*; D016615:Telomere / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D004272:DNA, Mitochondrial; D004044:Dietary Proteins; D017382:Reactive Oxygen Species; D000080242:8-Hydroxy-2'-Deoxyguanosine; D008715:Methionine; D019098:Telomerase; D003849:Deoxyguanosine