title: Serum levels of pigmentation markers are elevated in patients undergoing hemodialysis.
abstract: BACKGROUND
  Diffuse hyperpigmentation is common among patients with chronic renal failure undergoing hemodialysis (HD). We have examined serum levels of 5-S-cysteinyldopa (5SCD, a pheomelanin precursor), pheomelanin, eumelanin, and protein-bound (PB-) 3,4-dihydroxyphenylalanine (DOPA) and PB-5SCD in HD patients.
  
  
  METHODS
  Pheomelanin and eumelanin were assayed by chemical degradation methods.
  
  
  RESULTS
  Serum levels of free 5SCD in HD patients (n = 16) were 9-fold higher than in healthy controls (n = 16). Levels of pheomelanin in HD patients were 2.6-fold higher than in controls, while levels of eumelanin did not differ between HD patients and controls. Levels of PB-DOPA and PB-5SCD in HD patients were approximately 1.5-fold higher than in controls. Serum levels of free 5SCD were positively correlated to the duration of HD therapy.
  
  
  CONCLUSIONS
  The high constitutive levels of free 5SCD, pheomelanin, and PB-DOPA in the blood may be deteriorating in HD patients through the production of reactive oxygen species.
authors: Department of Nephrology, School of Medicine, Fujita Health University, Toyoake, Aichi, Japan.
authors: Kazutaka
authors: K
authors: Murakami
authors: Kazumasa
authors: K
authors: Wakamatsu
authors: Yukiko
authors: Y
authors: Nakanishi
authors: Hiroki
authors: H
authors: Takahashi
authors: Satoshi
authors: S
authors: Sugiyama
authors: Shosuke
authors: S
authors: Ito
mesh_terms: D015415:Biomarkers / Q000097:blood; D003548:Cysteinyldopa / Q000097:blood; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood / Q000628:therapy; D008543:Melanins / Q000097:blood*; D010860:Pigments, Biological / Q000097:blood*; D017382:Reactive Oxygen Species / Q000378:metabolism; D006435:Renal Dialysis / Q000009:adverse effects*
chemical_list: D015415:Biomarkers; D008543:Melanins; D010860:Pigments, Biological; D017382:Reactive Oxygen Species; C018362:pheomelanin; C041877:eumelanin; D003548:Cysteinyldopa