title: Asymmetric dimethylarginine in adults with cystathionine β-synthase deficiency.
abstract: In hyperhomocysteinemia (HHcy), an independent risk factor for cardiovascular diseases, endothelial dysfunction due to reduced bioavailability of nitric oxide is a consistent finding. However, the underlying mechanisms remain unknown. Increased levels of the nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) have been associated with HHcy, and may contribute, at least in part, for the homocysteine-induced endothelial dysfunction, but whether cystathionine β-synthase (CBS) deficiency is associated with increased ADMA has hardly been investigated. To address this question, we measured total homocysteine (tHcy), ADMA and symmetric dimethylarginine (SDMA) in plasma of 22 adult CBS deficient patients, using established HPLC techniques. Results showed that in CBS deficient patients with elevated levels of tHcy (median (total range): 33 (14-237) μmol/L), both ADMA and SDMA levels were normal. Moreover, tHcy and ADMA concentrations were not correlated (r(s)=0.017, p=0.94). Our results favor the hypothesis that the negative vascular effects of HHcy have an ADMA-independent etiology.
authors.affiliation: Department of Clinical Chemistry, Metabolic Unit, Institute for Cardiovascular Research (ICAR-VU), VU University Medical Center, Amsterdam, The Netherlands.
authors.forename: Monica S
authors.initials: MS
authors.lastname: Rocha
authors.forename: Tom
authors.initials: T
authors.lastname: Teerlink
authors.forename: Mirian C H
authors.initials: MC
authors.lastname: Janssen
authors.forename: Leo A J
authors.initials: LA
authors.lastname: Kluijtmans
authors.forename: Yvo
authors.initials: Y
authors.lastname: Smulders
authors.forename: Cornelis
authors.initials: C
authors.lastname: Jakobs
authors.forename: Isabel
authors.initials: I
authors.lastname: Tavares de Almeida
authors.forename: Isabel
authors.initials: I
authors.lastname: Rivera
authors.forename: Rita
authors.initials: R
authors.lastname: Castro
authors.forename: Henk J
authors.initials: HJ
authors.lastname: Blom
mesh_terms: D000328:Adult; D001120:Arginine / Q000031:analogs & derivatives* / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D004730:Endothelium, Vascular / Q000378:metabolism / Q000503:physiopathology; D006710:Homocysteine / Q000097:blood; D006712:Homocystinuria / Q000097:blood* / Q000503:physiopathology; D006801:Humans
chemical_list: D015415:Biomarkers; D006710:Homocysteine; C024917:symmetric dimethylarginine; C018524:N,N-dimethylarginine; D001120:Arginine