 |
| Research article summary (published 30 Aug 2009): |
Asymmetric dimethylarginine endogenous inhibition of nitric oxide synthase causes differential vasculature effects.
Full Abstract
BACKGROUND: Asymmetric dimethylarginine (ADMA), produced during protein metabolism, is an endogenous inhibitor of nitric oxide synthase, but little is known about its direct vasoactive properties in different arterial beds. MATERIAL/METHODS: Segments of canine coronary, renal, and femoral arteries were pretreated with increasing concentrations of ADMA, and endothelial function was evaluated in organ chambers. RESULTS: In precontracted canine coronary arteries, the highest concentrations of ADMA inhibited endothelium-dependent relaxation mediated by acetylcholine (n=7), but no concentration of ADMA inhibited receptor-independent relaxation mediated by calcium ionophore (n=7) (P<.001). The effect of ADMA on acetylcholine-mediated relaxation was shown to be competitive inhibition of the nitric oxide synthase pathway, because the addition of L-arginine (10(-3) M), but not D-arginine (10(-3) M), reversed the effect produced by 10-5 M ADMA. Further, ADMA did not alter endothelium-independent relaxation mediated by sodium nitroprusside (10(-9) to 10(-6) M; n=7). Femoral arteries (n=7) and renal arteries (n=7) were more sensitive to ADMA than were coronary arteries, and they demonstrated significant ADMA inhibition to receptor dependent relaxation induced by acetylcholine (P=.03 and P=.01, respectively) and to receptor-independent relaxation induced by calcium ionophore (P=.02 and P=.01, respectively). CONCLUSIONS: Endothelium-dependent relaxation mediated by ADMA is more marked in femoral and renal arteries than in coronary arteries. The response in coronary arteries may be overall protective. Considering these different effects in various artery types, the role of ADMA as a confiable and specific cardiovascular risk factor is questioned.
Author information
Author/s: Cable, David George (DG); Celotto, Andrea Carla (AC); Evora, Paulo Roberto Barbosa (PR); Schaff, Hartzell Vernon (HV);
Affiliation: Division of Cardiovascular Surgery, Mayo Clinic, Rochester, MN, USA.
Journal and publication information
Publication Type: Journal Article; Research Support, Non-U.S. Gov't
Journal: Medical science monitor : international medical journal of experimental and clinical research (Med Sci Monit), published in Poland. (Language: eng)
Reference: 2009-Sep; vol 15 (issue 9) : pp BR248-53
Dates: Created 2009/09/01; Completed 2009/11/02;
PMID: 19721392, status: MEDLINE (last retrieval date: 11/2/2009, IMS Date: )
Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.
External Links for this article
(including full text providers, if available):
Click Electronic Full-text Provider Links to see options for finding the electronic full text links to this article. Note there may be a subscription or fee required for access to the full text. See our FAQ for information on finding FREE full text articles.
This article may also be located in paper journal collections available in many libraries. Use the Journal and Publication Information above to find the full article.
MeSH headings (categories)
This article was linked to the MESH Headings shown below.
Related articles
This article has not been indexed for related articles as yet, however you can still use the live related article search links below.
See a large map of 100+ related articles.