title: Accumulation of zinc in human atherosclerotic lesions correlates with calcium levels but does not protect against protein oxidation.
abstract: OBJECTIVE
  Oxidized lipids and proteins, as well as decreased antioxidant levels, have been detected in human atherosclerotic lesions, with oxidation catalyzed by iron and copper postulated to contribute to lesion development. Zinc has been postulated to displace iron from critical sites and thereby protect against damage. In this study, metal ion and protein oxidation levels were quantified in human carotid and abdominal artery specimens containing early-to-advanced lesions, to determine whether zinc concentrations correlate inversely with iron levels and protein oxidation.
  
  
  RESULTS
  Metal ions were quantified by EPR and inductively coupled plasma mass spectroscopy. Native and oxidized protein side-chains were quantified by high-performance liquid chromatography. Elevated levels of zinc ( approximately 6-fold) were detected in advanced lesions compared to healthy tissue or early lesions. Zinc did not correlate negatively with iron or copper levels suggesting that zinc does not displace these metal ions. Highly significant positive correlations (P<0.005) were detected between zinc and calcium levels.
  
  
  CONCLUSIONS
  Zinc did not correlate with low iron levels and reduced protein oxidation. These data indicate that zinc does not prevent protein oxidation in advanced lesions. The reported protective effect of zinc accumulation is proposed to be associated with lesion calcification.
authors.affiliation: The Heart Research Institute, 114 Pyrmont Bridge Road, Camperdown, Sydney, NSW 2050, Australia.
authors.forename: Nadina
authors.initials: N
authors.lastname: Stadler
authors.forename: Naomi
authors.initials: N
authors.lastname: Stanley
authors.forename: Sylvia
authors.initials: S
authors.lastname: Heeneman
authors.forename: Vladimir
authors.initials: V
authors.lastname: Vacata
authors.forename: Mat J A P
authors.initials: MJ
authors.lastname: Daemen
authors.forename: Paul G
authors.initials: PG
authors.lastname: Bannon
authors.forename: Johannes
authors.initials: J
authors.lastname: Waltenberger
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Davies
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002118:Calcium / Q000378:metabolism*; D002340:Carotid Artery Diseases / Q000378:metabolism* / Q000473:pathology; D016893:Carotid Stenosis / Q000378:metabolism* / Q000473:pathology; D003300:Copper / Q000378:metabolism; D006801:Humans; D007501:Iron / Q000378:metabolism; D008875:Middle Aged; D010084:Oxidation-Reduction; D011506:Proteins / Q000378:metabolism*; D015032:Zinc / Q000378:metabolism*
chemical_list: D011506:Proteins; D003300:Copper; D007501:Iron; D015032:Zinc; D002118:Calcium