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In vivo creatine kinase reaction kinetics at rest and stress in type II diabetic rat heart
The effects of type II diabetes on cardiac creatine kinase (CK) enzyme activity and/or flux are unknown. We therefore measured steady‐state phosphocreatine (PCr) and adenosine triphosphate (ATP) content and forward CK reaction kinetic parameters in Zucker Diabetic Fatty (ZDF) rat hearts, a type II d...
Autores principales: | , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Wiley Periodicals, Inc.
2015
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Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387746/ https://www.ncbi.nlm.nih.gov/pubmed/25626865 http://dx.doi.org/10.14814/phy2.12248 |
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author | Bashir, Adil Coggan, Andrew R. Gropler, Robert J. |
author_facet | Bashir, Adil Coggan, Andrew R. Gropler, Robert J. |
author_sort | Bashir, Adil |
collection | PubMed |
description | The effects of type II diabetes on cardiac creatine kinase (CK) enzyme activity and/or flux are unknown. We therefore measured steady‐state phosphocreatine (PCr) and adenosine triphosphate (ATP) content and forward CK reaction kinetic parameters in Zucker Diabetic Fatty (ZDF) rat hearts, a type II diabetes research model. At baseline the PCr to ATP ratio (PCr/ATP) was significantly lower in diabetic heart when compared with matched controls (1.71 ± 0.21 vs. 2.26 ± 0.24, P < 0.01). Furthermore, the forward CK reaction rate constant (k(f)) was higher in diabetic animals (0.52 ± 0.09 s(−1) vs. 0.35 ± 0.06 s(−1), P < 0.01) and CK flux calculated as a product of PCr concentration ([PCr]) and k(f) was similar between two groups (4.32 ± 1.05 μmol/g/s vs. 4.94 ± 1.23 μmol/g/s, P = 0.20). Dobutamine administration resulted in similar increases in heart rate (~38%) and k(f) (~0.12 s(−1)) in both groups. No significant change in PCr and ATP content was observed with dobutamine. In summary, our data showed reduced PCr/ATP in diabetic myocardium as an indicator of cardiac energy deficit. The forward CK reaction rate constant is elevated at baseline which might reflect a compensatory mechanics to support energy flux through the CK shuttle and maintain constant ATP supply. When hearts were stimulated similar increase in k(f) was observed in both groups thus it seems that CK shuttle does not limit ATP supply for the range of workload studied. |
format | Online Article Text |
id | pubmed-4387746 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2015 |
publisher | Wiley Periodicals, Inc. |
record_format | MEDLINE/PubMed |
spelling | pubmed-43877462015-04-13 In vivo creatine kinase reaction kinetics at rest and stress in type II diabetic rat heart Bashir, Adil Coggan, Andrew R. Gropler, Robert J. Physiol Rep Original Research The effects of type II diabetes on cardiac creatine kinase (CK) enzyme activity and/or flux are unknown. We therefore measured steady‐state phosphocreatine (PCr) and adenosine triphosphate (ATP) content and forward CK reaction kinetic parameters in Zucker Diabetic Fatty (ZDF) rat hearts, a type II diabetes research model. At baseline the PCr to ATP ratio (PCr/ATP) was significantly lower in diabetic heart when compared with matched controls (1.71 ± 0.21 vs. 2.26 ± 0.24, P < 0.01). Furthermore, the forward CK reaction rate constant (k(f)) was higher in diabetic animals (0.52 ± 0.09 s(−1) vs. 0.35 ± 0.06 s(−1), P < 0.01) and CK flux calculated as a product of PCr concentration ([PCr]) and k(f) was similar between two groups (4.32 ± 1.05 μmol/g/s vs. 4.94 ± 1.23 μmol/g/s, P = 0.20). Dobutamine administration resulted in similar increases in heart rate (~38%) and k(f) (~0.12 s(−1)) in both groups. No significant change in PCr and ATP content was observed with dobutamine. In summary, our data showed reduced PCr/ATP in diabetic myocardium as an indicator of cardiac energy deficit. The forward CK reaction rate constant is elevated at baseline which might reflect a compensatory mechanics to support energy flux through the CK shuttle and maintain constant ATP supply. When hearts were stimulated similar increase in k(f) was observed in both groups thus it seems that CK shuttle does not limit ATP supply for the range of workload studied. Wiley Periodicals, Inc. 2015-01-27 /pmc/articles/PMC4387746/ /pubmed/25626865 http://dx.doi.org/10.14814/phy2.12248 Text en © 2015 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of the American Physiological Society and The Physiological Society. http://creativecommons.org/licenses/by/4.0/ This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Original Research Bashir, Adil Coggan, Andrew R. Gropler, Robert J. In vivo creatine kinase reaction kinetics at rest and stress in type II diabetic rat heart |
title | In vivo creatine kinase reaction kinetics at rest and stress in type II diabetic rat heart |
title_full | In vivo creatine kinase reaction kinetics at rest and stress in type II diabetic rat heart |
title_fullStr | In vivo creatine kinase reaction kinetics at rest and stress in type II diabetic rat heart |
title_full_unstemmed | In vivo creatine kinase reaction kinetics at rest and stress in type II diabetic rat heart |
title_short | In vivo creatine kinase reaction kinetics at rest and stress in type II diabetic rat heart |
title_sort | in vivo creatine kinase reaction kinetics at rest and stress in type ii diabetic rat heart |
topic | Original Research |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387746/ https://www.ncbi.nlm.nih.gov/pubmed/25626865 http://dx.doi.org/10.14814/phy2.12248 |
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