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. 2007 S. Karger AG, Basel
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 HDpatients. METHODS:Pheomelanin and eumelanin were assayed by chemical degradation methods. RESULTS: Serum levels of free 5SCD in HDpatients (n = 16) were 9-fold higher than in healthy controls (n = 16). Levels of pheomelanin in HDpatients were 2.6-fold higher than in controls, while levels of eumelanin did not differ between HDpatients and controls. Levels of PB-DOPA and PB-5SCD in HDpatients 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 HDpatients through the production of reactive oxygen species. 2007 S. Karger AG, Basel
Authors: B Güvercin; K Kaynar; D A Arıca; B V Kural; Ş Ulusoy; M Cansız; L B Selçuk; A Akyüz; C C Kolaylı Journal: Hippokratia Date: 2019 Apr-Jun Impact factor: 0.471