Document Detail


The Cycling of Acetyl-CoA through Acetylcarnitine Buffers Cardiac Substrate Supply: A Hyperpolarised 13C Magnetic Resonance Study.
MedLine Citation:
PMID:  22238215     Owner:  NLM     Status:  Publisher    
Abstract/OtherAbstract:
BACKGROUND: -Carnitine acetyltransferase (CAT) catalyses the reversible conversion of acetyl-CoA into acetylcarnitine. The aim of this study was to use the metabolic tracer hyperpolarised [2-(13)C]pyruvate with magnetic resonance spectroscopy (MRS) to determine if CAT facilitates carbohydrate oxidation in the heart. METHODS AND RESULTS: -Ex vivo, following hyperpolarised [2-(13)C]pyruvate infusion, the [1-(13)C]acetylcarnitine MR resonance was saturated with a radiofrequency pulse and the effect of this saturation on [1-(13)C]citrate and [5-(13)C]glutamate was observed. In vivo, [2-(13)C]pyruvate was infused into three groups of fed male Wistar rats; (a) controls, (b) rats in which dichloroacetate enhanced PDH flux and (c) rats in which dobutamine elevated cardiac workload. In the perfused heart, [1-(13)C]acetylcarnitine saturation reduced the [1-(13)C]citrate and [5-(13)C]glutamate resonances by 63% and 51%, indicating rapid exchange between pyruvate-derived acetyl-CoA and the acetylcarnitine pool. In vivo, dichloroacetate increased the rate of [1-(13)C]acetylcarnitine production by 35% and increased the overall acetylcarnitine pool size by 33%. Dobutamine decreased the rate of [1-(13)C]acetylcarnitine production by 37% and decreased the acetylcarnitine pool size by 40%. CONCLUSIONS: -Hyperpolarised (13)C MRS has revealed that acetylcarnitine provides a route of disposal for excess acetyl-CoA, and also a means to replenish acetyl-CoA when cardiac workload is increased. Cycling of acetyl-CoA through acetylcarnitine appears key to matching instantaneous acetyl-CoA supply with metabolic demand, thereby helping to balance myocardial substrate supply and contractile function.
Authors:
Marie A Schroeder; Helen J Atherton; Michael S Dodd; Phillip Lee; Lowri E Cochlin; George K Radda; Kieran Clarke; Damian J Tyler
Related Documents :
20398415 - Mdct findings of denim-sandblasting-induced silicosis: a cross-sectional study.
12511695 - Detection of pulmonary metastases with multi-detector row ct scans of 5-mm nominal sect...
15984975 - Outcome of small (10-20 mm) arterial phase-enhancing nodules seen on triphasic liver ct...
19253205 - Transthoracic sonography for the detection of pulmonary embolism--a meta-analysis.
18176145 - Stir mri to direct muscle biopsy in suspected idiopathic inflammatory myopathy.
11105045 - Magnetic resonance imaging of the primary site in stage i cervical carcinoma: a compari...
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2012-1-11
Journal Detail:
Title:  Circulation. Cardiovascular imaging     Volume:  -     ISSN:  1942-0080     ISO Abbreviation:  -     Publication Date:  2012 Jan 
Date Detail:
Created Date:  2012-1-12     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  101479935     Medline TA:  Circ Cardiovasc Imaging     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Affiliation:
University of Oxford, Oxford, United Kingdom.
Export Citation:
APA/MLA Format     Download EndNote     Download BibTex
MeSH Terms
Descriptor/Qualifier:

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


Previous Document:  When and why do retrieval attempts enhance subsequent encoding?
Next Document:  Metabolic syndrome, physical activity and cardiac autonomic function.