| Bio-energetic impairment in human calf muscle in thyroid disorders: a 31P MRS study. | |
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MedLine Citation:
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PMID: 20332062 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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Mitochondrial metabolism particularly oxidative phosphorylation is greatly influenced by thyroid hormones. Earlier studies have described neuromuscular symptoms as well as impaired muscle metabolism in hypothyroid and hyperthyroid patients. In this study, we intend to look in to the muscle bioenergetics including phosphocreatine recovery kinetics based oxidative metabolism in thyroid dysfunction using in vivo (31)P nuclear magnetic resonance spectroscopy (MRS). (31)P MRS was carried out at resting state on 32 hypothyroid, 10 hyperthyroid patients and 25 control subjects. Nine out of 32 hypothyroid patients and 17 out of 25 control subjects under went exercise protocol for oxidative metabolism study and performed plantar flexion exercise while lying supine in 1.5 T magnetic resonance scanner using custom built exercise device. MRS measurements of inorganic phosphate (Pi), phosphocreatine (PCr), phosphodiesters (PDE) and adenosine triphosphate (ATP) of the calf muscle were acquired during rest, exercise and recovery phase. PCr recovery rate constant (k(PCr)) and oxidative capacity were calculated by monoexponential fit of PCr versus time (t) at the beginning of recovery. During resting condition in hypothyroid patients, PCr/Pi ratio was reduced whereas PDE/ATP and Pi/ATP were increased. However, in case of hyperthyroidism, an increased PCr/Pi ratio and reduced PDE/ATP and Pi/ATP were observed. The results confirmed differential energy status of the muscle due to increased or decreased levels of thyroid hormone. Our results also demonstrate reduced oxidative metabolism in hypothyroid patients based on PCr recovery kinetics. PCr recovery kinetics study after exercise revealed decreased PCr recovery rate constant (k(PCr)) in hypothyroid patients compared to controls that resulted in decrease in oxidative capacity of muscle by 50% in hypothyroids. These findings are consistent with a defect of high energy phosphate mitochondrial metabolism in thyroid dysfunction. |
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Authors:
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Subash Khushu; Poonam Rana; Tarun Sekhri; Gopalakrishnan Sripathy; Rajendra Prasad Tripathi |
Publication Detail:
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Type: Journal Article Date: 2010-03-23 |
Journal Detail:
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Title: Magnetic resonance imaging Volume: 28 ISSN: 1873-5894 ISO Abbreviation: Magn Reson Imaging Publication Date: 2010 Jun |
Date Detail:
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Created Date: 2010-05-21 Completed Date: 2010-09-28 Revised Date: - |
Medline Journal Info:
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Nlm Unique ID: 8214883 Medline TA: Magn Reson Imaging Country: Netherlands |
Other Details:
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Languages: eng Pagination: 683-9 Citation Subset: IM |
Copyright Information:
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Copyright 2010 Elsevier Inc. All rights reserved. |
Affiliation:
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NMR Research Centre, INMAS, DRDO, Timarpur, Delhi, India. skhushu@yahoo.com |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Adolescent Adult Child Energy Metabolism Female Humans Hypothyroidism / diagnosis*, metabolism* Magnetic Resonance Spectroscopy / methods* Male Metabolic Clearance Rate Middle Aged Muscle, Skeletal / metabolism* Phosphocreatine / analysis* Phosphorus Isotopes / analysis Thigh Young Adult |
| Chemical | |
Reg. No./Substance:
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0/Phosphorus Isotopes; 67-07-2/Phosphocreatine |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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