title: [Tryptophan and its metabolites in renal allograft recipients].
abstract: OBJECTIVE
  Disturbances in amino acids metabolism are common in chronic renal failure and subside partially after renal tranplantation. Tryptophan (TRP) is one of the most important exogenous amino acids. Its main derivative is L-kynurenine (KYN). Disorders in the TRP metabolism via kynurenine pathway may lead to neurologic disturbances, hypertension and anaemia. The aim of this study was to assess peripheral kynurenine pathway in 28 renal allograft recipients (RAR) (12 women and 16 men) in comparison to 10 hemodialysed patients with chronic renal failure (CRF) and 10 healthy subjects.
  
  
  METHODS
  TRP, KYN, 3-hydroxykynurenine (3-HKYN), kyn-urenic acid (KYNA) and quinolinic acid (QA) were determined in plasma using high performance liquid chromatography technique.
  
  
  RESULTS
  The plasma concentration of tryptophan in RAR was not significantly different from the control group, but it was almost twice higher than in CRF. There was an increase in most of kynurenine metabolites in RAR as compared to healthy subjects, although not as high as in CRF. We found a significant negative correlation between TRP and serum concentration of urea and creatinine as well as a positive correlation with GFR.
  
  
  CONCLUSIONS
  Kidney transplantation tends to normalize TRP level and markedly lowers blood concentration of kynurenine and its main derivatives. A significant negative correlation was found between TRP level and the concentration of urea and creatinine. Lowering of the KYN metabolites level may play a role in lessening uremic neurological symptomes as well as hypertension and anemia in kidney graft recipients.
authors.affiliation: I Klinika Chirurgii Ogólnej i Endokrynologicznej, Uniwersytet Medyczny w Białymstoku. mpiotr@umwb.edu.pl
authors.forename: Piotr
authors.initials: P
authors.lastname: Myśliwiec
authors.forename: Hanna
authors.initials: H
authors.lastname: Myśliwiec
authors.forename: Dariusz
authors.initials: D
authors.lastname: Pawlak
authors.forename: Jacek
authors.initials: J
authors.lastname: Dadan
authors.forename: Włodzimierz
authors.initials: W
authors.lastname: Buczko
authors.forename: Krystyna
authors.initials: K
authors.lastname: Pawlak
mesh_terms: D000328:Adult; D000368:Aged; D003404:Creatinine / Q000378:metabolism; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000378:metabolism; D016030:Kidney Transplantation / Q000502:physiology*; D007737:Kynurenine / Q000378:metabolism*; D050601:Kynurenine 3-Monooxygenase / Q000097:blood*; D008297:Male; D008875:Middle Aged; D017378:Quinolinic Acid / Q000097:blood*; D012016:Reference Values; D014364:Tryptophan / Q000097:blood*; D014508:Urea / Q000378:metabolism
chemical_list: D007737:Kynurenine; D014364:Tryptophan; D014508:Urea; D003404:Creatinine; D050601:Kynurenine 3-Monooxygenase; D017378:Quinolinic Acid