title: Effects of chromium picolinate on glycemic control and kidney of the obese Zucker rat.
abstract: BACKGROUND
  Chromium picolinate (Cr(pic)3) is advocated as adjuvant therapy for impaired glycemic control, despite concerns for DNA damage. Potential toxicity of Cr(pic)3 should be greater for the kidney that accumulates chromium. Therefore, we tested the hypothesis that Cr(pic)3 treatment of obese Zucker rats (OZR) exacerbates renal abnormalities associated with dysglycemia.
  
  
  METHODS
  Male OZR were treated with diets lacking or containing 5 and 10 mg/kg of chromium, as Cr(pic)3, for 20 weeks; lean Zucker rats (LZR) served as controls. Glycemic and renal effects of Cr(pic)3 were determined in the context of indices of oxidative stress and inflammation.
  
  
  RESULTS
  The OZR displayed increased fasting plasma glucose and insulin in association with enlarged pancreatic islets exhibiting collagen and periodic acid Schiff-positive deposits compared to LZR; Cr(pic)3 treatment did not affect these parameters. The OZR, irrespective of Cr(pic)3, excreted more albumin than LZR. Also, other indices of renal function or histopathology were not affected by Cr(pic)3 treatment. Urinary excretion of 8-hydroxydeoxyguanosine (8-OHdG), an index of oxidative DNA damage, was greater in the OZR than LZR; dietary Cr(pic)3 treatment attenuated 8-OHdG excretion. However, immunostaining of kidney for 8-OHdG revealed similar staining pattern and intensity, despite significant renal accumulation of chromium in Cr(pic)3-treated groups. Finally, increased renal nitrotyrosine and cyclooxygenase-2 levels and urinary excretion of monocyte chemoattractant protein-1 of OZR were partially reversed by Cr(pic)3 treatment.
  
  
  CONCLUSIONS
  Dietary Cr(pic)3 treatment of OZR does not beneficially influence glycemic status or increase the risk for oxidative DNA damage; rather, the treatment attenuates indices of oxidative stress and inflammation.
authors.affiliation: Department of Oral Biology, School of Dentistry, Medical College of Georgia Augusta, Georgia 30912, USA. Mmozaffa@mail.mcg.edu.
authors.forename: Mahmood S
authors.initials: MS
authors.lastname: Mozaffari
authors.forename: Rafik
authors.initials: R
authors.lastname: Abdelsayed
authors.forename: Jun Yao
authors.initials: JY
authors.lastname: Liu
authors.forename: Hereward
authors.initials: H
authors.lastname: Wimborne
authors.forename: Azza
authors.initials: A
authors.lastname: El-Remessy
authors.forename: Ahmed
authors.initials: A
authors.lastname: El-Marakby