title: Free cysteine is increased in plasma from hemodialysis patients.
abstract: BACKGROUND
  Although only the total thiol concentration, which includes bound and free forms, has been determined in most previous clinical studies, the free form may be a better predictor of cardiovascular risk.
  
  
  METHODS
  We measured the apparent concentration of free homocysteine (Hcy) and cysteine (Cys) in filtered and acid-soluble fractions of plasma in healthy control subjects and in patients with chronic renal failure just before and after a hemodialysis session.
  
  
  RESULTS
  In control, filtered Hcy and acid-soluble Hcy were similar, while filtered Cys was much smaller than in acid-soluble Cys. In prehemodialysis samples, filtered Cys was more than 60 times as abundant (259.2 +/- 26.2 micromol/L) as in control samples (4.1 +/- 0.7 micromol/L ). Free-to-total ratios for filtered Cys were 1.6 +/- 0.3% in controls, but 40.9 +/- 2.7% in prehemodialysis patients.
  
  
  CONCLUSIONS
  The filtered fraction of thiols can be used to estimate solute transport across the dialysis membrane. In addition, the possible involvement of cysteine in the pathogenesis of atherosclerosis in hemodialysis patients should be reexamined.
authors.affiliation: Department of Internal Medicine, Hyogo College of Medicine, Nishinomiya, Japan. t-nknd@hyo-med.ac.jp
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nakanishi
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Hasuike
authors.forename: Yoshinaga
authors.initials: Y
authors.lastname: Otaki
authors.forename: Yasue
authors.initials: Y
authors.lastname: Hama
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Nanami
authors.forename: Koji
authors.initials: K
authors.lastname: Miyagawa
authors.forename: Rintaro
authors.initials: R
authors.lastname: Moriguchi
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Nishikage
authors.forename: Masaaki
authors.initials: M
authors.lastname: Izumi
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Takamitsu
mesh_terms: D000143:Acids; D000328:Adult; D003545:Cysteine / Q000097:blood*; D005260:Female; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007676:Kidney Failure, Chronic / Q000097:blood* / Q000628:therapy*; D008297:Male; D008875:Middle Aged; D006435:Renal Dialysis; D012995:Solubility; D013438:Sulfhydryl Compounds / Q000097:blood
chemical_list: D000143:Acids; D013438:Sulfhydryl Compounds; D006710:Homocysteine; D003545:Cysteine