title: Aged rats are susceptible to nephrotoxicity induced by iodinated contrast media.
abstract: OBJECTIVE
  The objective of this study is to evaluate the effect and mechanism of aging on iodinated-contrast-media-induced nephropathy in male rats.
  
  
  METHODS
  Twenty-four healthy male rats were initially divided into 12-month-old and 24-month-old age groups (adult and older age groups, respectively; n = 12/group); subsequently, each age group was randomly divided into saline control (NS) and contrast media (CM) groups (n = 6/group). CM (76% diatrizoate, 10 mL/kg b.w.) was given through the caudal vein. Urinary creatinine (Ucr) and serum creatinine (Scr) were detected by an automatic biochemical analyzer. The activities of renal malondialdehyde (MDA), superoxide dismutase (SOD), angiotensin-converting enzyme (ACE), angiotensin II (Ang II), and reduced form of nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase) were determined by spectrophotometric assays with commercially available kits according to the manufacturers' protocols. Renal histological changes were observed by hematoxylin and eosin staining and scored semiquantitatively.
  
  
  RESULTS
  In diatrizoate-injected aged rats, Scr, the activities of ACE, Ang II, MDA, and NADPH oxidase in renal tissues were significantly increased (p < 0.01). The histologic scores were higher in the aged animals with CM treatment than those of control or adult rats (p < 0.01). There was an increasing trend but no significant statistical difference in renal ACE, Ang II, MDA, and NADPH oxidase or histologic scores in adult CM-injected rats compared with control animals (p > 0.05).
  
  
  CONCLUSIONS
  Older age is an aggravating factor of iodinated-contrast-media-induced nephropathy in male rats. Oxidative stress and the renin-angiotensin system (RAS) may play an important role in nephrotoxicity induced by iodinated contrast media, especially in aged male rats.
authors.affiliation: Institute of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, PR China. DuanSB528@hotmail.com
authors.forename: Shao-Bin
authors.initials: SB
authors.lastname: Duan
authors.forename: Gai-Ling
authors.initials: GL
authors.lastname: Liu
authors.forename: Guo-Chun
authors.initials: GC
authors.lastname: Chen
authors.forename: Pian
authors.initials: P
authors.lastname: Wang
authors.forename: Peng
authors.initials: P
authors.lastname: Pan
authors.forename: Xiang-Qing
authors.initials: XQ
authors.lastname: Xu
mesh_terms: D000375:Aging / Q000187:drug effects*; D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D003287:Contrast Media / Q000633:toxicity*; D003974:Diatrizoate Meglumine / Q000633:toxicity*; D004195:Disease Models, Animal; D007668:Kidney / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D007674:Kidney Diseases / Q000139:chemically induced* / Q000378:metabolism / Q000473:pathology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D009249:NADP / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology*; D013482:Superoxide Dismutase / Q000378:metabolism
chemical_list: D003287:Contrast Media; D000804:Angiotensin II; D003974:Diatrizoate Meglumine; D008315:Malondialdehyde; D009249:NADP; D013482:Superoxide Dismutase