title: The arginine-creatine pathway is disturbed in children and adolescents with renal transplants.
abstract: Cardiovascular disease is an important cause of morbidity in recipients of renal transplants. The aim of the present study was to analyze the status of the arginine-creatine pathway in such patients, given the relationship between the arginine metabolism and both renal function and the methionine-homocysteine cycle. Twenty-nine children and adolescents (median age 13, range 6-18 years), who had received a renal allograft 14.5-82.0 months before, were recruited for the study. On immunosuppressive therapy, all patients evidenced an adequate level of renal function. Plasma concentrations of homocysteine and glycine were significantly higher, whereas urinary excretions of guanidinoacetate and creatine were significantly lower than controls. Urinary excretions of guanidinoacetate and creatine correlated positively with creatinine clearance. Urinary excretion of creatine was negatively correlated with plasma concentration of homocysteine. The demonstration of disturbances in the arginine-creatine pathway in patients with well-functioning renal transplants and in absence of chronic renal failure represents a novel finding. We speculate that the low urinary excretion of guanidinoacetate and creatine is probably related to the nephrotoxic effect of immunosuppressive therapy and to defective methylation associated with the presence of hyperhomocysteinemia.
authors.affiliation: Department of Pediatrics, Division of Metabolism, Cruces Hospital, Bilbao, Basque Country, Spain.
authors.forename: Fernando
authors.initials: F
authors.lastname: Andrade
authors.forename: Juan
authors.initials: J
authors.lastname: Rodríguez-Soriano
authors.forename: José Angel
authors.initials: JA
authors.lastname: Prieto
authors.forename: Javier
authors.initials: J
authors.lastname: Elorz
authors.forename: Mireia
authors.initials: M
authors.lastname: Aguirre
authors.forename: Gema
authors.initials: G
authors.lastname: Ariceta
authors.forename: Sergio
authors.initials: S
authors.lastname: Martin
authors.forename: Pablo
authors.initials: P
authors.lastname: Sanjurjo
authors.forename: Luis
authors.initials: L
authors.lastname: Aldámiz-Echevarría
mesh_terms: D000293:Adolescent; D001120:Arginine / Q000378:metabolism*; D002318:Cardiovascular Diseases / Q000453:epidemiology; D016022:Case-Control Studies; D002648:Child; D003401:Creatine / Q000378:metabolism*; D003404:Creatinine / Q000652:urine; D005260:Female; D005998:Glycine / Q000031:analogs & derivatives / Q000097:blood / Q000652:urine; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology; D007668:Kidney / Q000187:drug effects / Q000378:metabolism*; D016030:Kidney Transplantation; D008297:Male; D008745:Methylation; D012307:Risk Factors
chemical_list: D007166:Immunosuppressive Agents; D006710:Homocysteine; D001120:Arginine; D003404:Creatinine; C004946:glycocyamine; D003401:Creatine; D005998:Glycine