Chronic dietary L-arginine down-regulates adenosine receptor and nitric oxide synthase expression in rat heart
Article
Article Title | Chronic dietary L-arginine down-regulates adenosine receptor and nitric oxide synthase expression in rat heart |
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ERA Journal ID | 14693 |
Article Category | Article |
Authors | Rose'Meyer, Roselyn B. (Author), Harrison, Glenn (Author), Fenning, Andrew (Author), Jenner, Tamsin (Author) and Brown, Lindsay (Author) |
Journal Title | Basic and Clinical Pharmacology and Toxicology |
Journal Citation | 102 (5), pp. 459-465 |
Number of Pages | 7 |
Year | 2008 |
Place of Publication | Oxford, United Kingdom |
ISSN | 0901-9928 |
1742-7835 | |
1742-7843 | |
Digital Object Identifier (DOI) | https://doi.org/10.1111/j.1742-7843.2008.00209.x |
Web Address (URL) | http://onlinelibrary.wiley.com/doi/10.1111/j.1742-7843.2008.00209.x/pdf |
Abstract | L-Arginine increases myocardial nitric oxide production. Nitric oxide mediates many of the cardiovascular actions of adenosine and modulates adenosine metabolism. In this study, we examined the effect of chronic l-arginine (5%) intake on cardiac nitric oxide synthase (NOS) and adenosine receptor expression and cardiac function in rat Langendorff-isolated perfused hearts. Our results show that 4-week chronic l-arginine ingestion increases the weight of rat hearts by 17.6% (P < 0.05). l-Arginine treatment decreased the expression of all the cardiac adenosine receptors, with reductions in adenosine A1 (20-fold), A2A (7.7-fold), A2B (76-fold) and A3 (25.6-fold) mRNA (P < 0.05). NOS expression was variably affected with no change in the expression of NOS1 and 4.2-fold down-regulation of NOS3 expression with chronic l-arginine treatment (P < 0.05). NOS2 was expressed in control tissues; however, in l-arginine-treated hearts the amount of NOS2 mRNA was reduced to non-detectable levels. Following chronic l-arginine treatment, an increase in coronary perfusion pressure was observed (P < 0.05). Purine efflux was used as an indicator of metabolic efficiency. l-Arginine did not alter catecholamine-induced purine efflux (P > 0.05); however, noradrenaline-mediated increases in contractility and myocardial oxygen consumption were reduced. Vasodilator responses to 5′-N-ethylcarboxamidoadenosine (NECA) were reduced in hearts from l-arginine-treated rats and the NOS inhibitor Nω-nitro-l-arginine methyl ester (3 μM) did not inhibit responses to NECA. In conclusion, 4-week dietary supplementation of l-arginine reduced the expression of cardiac adenosine receptors and NOSs with a subsequent decrease in noradrenaline-stimulated cardiac function and adenosine receptor-mediated coronary vasodilation. |
Keywords | animal tissue; dietary intake; heart function; heart muscle contractility; heart muscle oxygen consumption; heart perfusion; heart weight; ingestion; isolated heart; perfusion pressure; protein expression; receptor down regulation; vasodilatation |
ANZSRC Field of Research 2020 | 320507. Metabolic medicine |
321099. Nutrition and dietetics not elsewhere classified | |
320101. Cardiology (incl. cardiovascular diseases) | |
Public Notes | File reproduced in accordance with the copyright policy of the publisher/author. |
Byline Affiliations | Griffith University |
Office of Research | |
University of Queensland | |
Institution of Origin | University of Southern Queensland |
https://research.usq.edu.au/item/q0w42/chronic-dietary-l-arginine-down-regulates-adenosine-receptor-and-nitric-oxide-synthase-expression-in-rat-heart
1928
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