title: Methionine-centered redox cycle in organs of the aero-digestive tract of young and old rats.
abstract: It is commonly accepted that aging is associated with a decline in the antioxidant defense of the cell; accordingly, certain redox enzymes are used as markers of biological senescence. To further test and specify this general concept, we studied age-related changes in the enzymes of the methionine-centered redox cycle (MCRC) in four aero-digestive organs of rats. The levels of cytosolic thioredoxin (Trx), thioredoxin reductase (TrxR), and methionine sulfoxide reductase (Msr), all tended to decline with age. The enzymatic activities of MsrA and MsrB were significantly lower in the organs of aged animals. In general, the magnitude of this decline increased in the order: tongue < sternohyoid muscle < larynx < esophagus. The relative stability of MCRC in the old tongues might be part of the well-preserved oxidative metabolism as confirmed by the age-related increase in mitochondrial marker and muscle tissue in these tongues. In total, the results suggest that age-associated oxidative damage is organ-specific and could reflect differences in morphological composition of these tissues, and among them, relative content of striated muscles.
authors.affiliation: Department of Cellular Biochemistry and Human Genetics, The Hebrew University of Jerusalem, IL, Israel.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Vinokur
authors.forename: Leonid
authors.initials: L
authors.lastname: Grinberg
authors.forename: Eduard
authors.initials: E
authors.lastname: Berenshtein
authors.forename: Menachem
authors.initials: M
authors.lastname: Gross
authors.forename: Jackob
authors.initials: J
authors.lastname: Moskovitz
authors.forename: Abraham Z
authors.initials: AZ
authors.lastname: Reznick
authors.forename: Mordechai
authors.initials: M
authors.lastname: Chevion
authors.forename: Ron
authors.initials: R
authors.lastname: Eliashar
mesh_terms: D000367:Age Factors; D000375:Aging / Q000378:metabolism*; D000818:Animals; D003576:Electron Transport Complex IV / Q000378:metabolism; D004947:Esophagus / Q000201:enzymology; D005260:Female; D041981:Gastrointestinal Tract / Q000201:enzymology*; D007830:Larynx / Q000201:enzymology; D008715:Methionine / Q000378:metabolism*; D051150:Methionine Sulfoxide Reductases; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D013880:Thioredoxin-Disulfide Reductase / Q000378:metabolism*; D013879:Thioredoxins / Q000378:metabolism*; D014059:Tongue / Q000201:enzymology
chemical_list: D013879:Thioredoxins; D008715:Methionine; D010088:Oxidoreductases; D013880:Thioredoxin-Disulfide Reductase; D051150:Methionine Sulfoxide Reductases; C488525:MsrA protein, rat; C027219:methionine sulfoxide reductase; D003576:Electron Transport Complex IV