title: Evidence of increased oxidative stress in aged mesenteric lymphatic vessels.
abstract: BACKGROUND
  We have previously shown that aging is associated with weakened rat mesenteric lymphatic vessel (MLV) contractility. However, the specific mechanisms contributing to this aging-associated contractile degeneration remain unknown. Aging is often associated with elevations in oxidative stress, and reactive oxygen species (ROS) have been shown to reduce the contractility of MLV. Thus in the present study, we sought to assess whether aging is associated with increased levels of oxidative stress and oxidative damage in MLV.
  
  
  RESULTS
  MLV were isolated from 9-mo- and 24-mo-old Fischer-344 rats and subjected to the following experimental techniques: measurement of total superoxide dismutase (SOD) activity; estimation of lipid peroxidation levels via measurement of thiobarbituric acid reactive substances (TBARS); detection of superoxide and mitochondrial ROS in live MLV; Western blot analysis, and immunohistochemical labeling of the SOD isoforms and nitro-tyrosine proteins. We found that aging is associated with increased levels of cellular superoxide and mitochondrial ROS concomitant with a reduction in Cu/Zn-SOD protein expression and total SOD enzymatic activity in MLV. This increase in oxidative stress and decrease in antioxidant activity was associated with evidence of increased lipid (as indicated by TBARS) and protein (as indicated by nitro-tyrosine labeling) oxidative damage.
  
  
  CONCLUSIONS
  Thus for the first time, we demonstrate that aging-associated increases in oxidative stress and oxidative damage is indeed present in the walls of MLV and may contribute to the aging-associated lymphatic pump dysfunction we previously reported.
authors.affiliation: Department of Systems Biology and Translational Medicine, College of Medicine, Texas A&M Health Science Center, Temple, Texas 76504, USA.
authors.forename: Sangeetha
authors.initials: S
authors.lastname: Thangaswamy
authors.forename: Eric A
authors.initials: EA
authors.lastname: Bridenbaugh
authors.forename: Anatoliy A
authors.initials: AA
authors.lastname: Gashev
mesh_terms: D000367:Age Factors; D000375:Aging / Q000378:metabolism*; D000818:Animals; D015153:Blotting, Western; D007150:Immunohistochemistry; D015227:Lipid Peroxidation; D042601:Lymphatic Vessels / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D008643:Mesentery / Q000201:enzymology / Q000378:metabolism*; D008928:Mitochondria / Q000378:metabolism; D018384:Oxidative Stress; D051381:Rats; D011916:Rats, Inbred F344; D017382:Reactive Oxygen Species / Q000378:metabolism; D013482:Superoxide Dismutase / Q000378:metabolism; D000072105:Superoxide Dismutase-1; D013481:Superoxides / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D000099156:Superoxide Dismutase 2
chemical_list: D017382:Reactive Oxygen Species; D013482:Superoxide Dismutase; D000072105:Superoxide Dismutase-1; D013481:Superoxides; D017392:Thiobarbituric Acid Reactive Substances; D014443:Tyrosine; D000099156:Superoxide Dismutase 2; C002744:3-nitrotyrosine; C000606292:Sod1 protein, rat; C499089:Sod3 protein, rat