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The heart requires glycerol as an energy substrate through aquaporin 7, a glycerol facilitator.
- Source :
-
Cardiovascular research [Cardiovasc Res] 2009 Jul 01; Vol. 83 (1), pp. 34-41. Date of Electronic Publication: 2009 Mar 18. - Publication Year :
- 2009
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Abstract
- Aims: Cardiomyocytes require fatty acids and glucose for energy production. However, other nutrients and substrates that may serve as possible candidates for a cardiac energy source have not been fully studied. Several reports showed that a moderate expression of aquaporin 7 (AQP7), a member of the aquaglyceroporin family that is permeated by glycerol and water, is observed in heart tissue. However, the functional role of cardiac AQP7 is not clear. The aim of this study was to investigate the significance of glycerol as a cardiac energy substrate and to clarify the role of cardiac AQP7.<br />Methods and Results: Heart function and morphology were examined in AQP7-knockout (KO) mice under basal conditions and during pressure overload [isoproterenol infusion and transverse aortic constriction (TAC)]. Glycerol uptake and glycerol-dependent ATP production were measured in AQP7-knockdown cardiac cells. Cardiac glycerol consumption was analysed in ex vivo beating hearts. Cardiac morphology and function in KO mice were similar to those of wild-type (WT) mice under basal conditions, although low glycerol and ATP content were noted in hearts of KO mice. In H9c2 cardiomyotubes, knockdown of AQP7 was associated with a significant reduction of glycerol uptake. The ex vivo heart study demonstrated that cardiac glycerol consumption levels in KO mice were significantly lower than those of WT mice. Furthermore, isoproterenol challenge induced severe left ventricular hypertrophy in KO mice, and TAC resulted in a higher mortality rate in KO mice than in WT mice.<br />Conclusion: The results indicate that AQP7 acts as a glycerol facilitator in cardiomyocytes and that glycerol is a substrate for cardiac energy production.
- Subjects :
- Adenosine Triphosphate metabolism
Animals
Aquaglyceroporins genetics
Aquaporins genetics
Cardiotonic Agents adverse effects
Fatty Acids metabolism
Glucose metabolism
Hypertrophy, Left Ventricular chemically induced
Hypertrophy, Left Ventricular pathology
Isoproterenol adverse effects
Mice
Mice, Inbred C57BL
Mice, Knockout
Models, Animal
Myocardium pathology
Myocytes, Cardiac metabolism
Myocytes, Cardiac pathology
Aquaglyceroporins metabolism
Aquaporins metabolism
Energy Metabolism physiology
Glycerol metabolism
Myocardium metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 1755-3245
- Volume :
- 83
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Cardiovascular research
- Publication Type :
- Academic Journal
- Accession number :
- 19297367
- Full Text :
- https://doi.org/10.1093/cvr/cvp095