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Changes in calcium fluxes in mitochondria, microsomes, and plasma membrane vesicles of livers from monosodium L-glutamate-obese rats.
- Source :
-
Metabolism: clinical and experimental [Metabolism] 2011 Oct; Vol. 60 (10), pp. 1433-41. Date of Electronic Publication: 2011 Apr 12. - Publication Year :
- 2011
-
Abstract
- The purpose of this work was to evaluate if the fat liver accumulation interferes with intracellular calcium fluxes and the liver glycogenolytic response to a calcium-mobilizing α(1)-adrenergic agonist, phenylephrine. The animal model of monosodium L-glutamate (MSG)-induced obesity was used. The adult rats develop obesity and steatosis. Calcium fluxes were evaluated through measuring the (45)Ca(2+) uptake by liver microsomes, inside-out plasma membrane, and mitochondria. In the liver, assessments were performed on the calcium-dependent glycogenolytic response to phenylephrine and the glycogen contents. The Ca(2+) uptake by microsomes and plasma membrane vesicles was reduced in livers from obese rats as a result of reduction in the Ca(2+)-ATPase activities. In addition, the plasma membrane Na(+)/K(+)-ATPase was reduced. All these matched effects could contribute to elevated resting intracellular calcium levels in the hepatocytes. Livers from obese rats, albeit smaller and with similar glycogen contents to those of control rats, released higher amounts of glucose in response to phenylephrine infusion, which corroborates these observations. Mitochondria from obese rats exhibited a higher capacity of retaining calcium, a phenomenon that could be attributed to a minor susceptibility of the mitochondrial permeability transition pore opening.<br /> (Copyright © 2011 Elsevier Inc. All rights reserved.)
- Subjects :
- Adenosine Triphosphate pharmacology
Animals
Animals, Newborn
Cell Membrane drug effects
Cell Membrane pathology
Glycogenolysis drug effects
Glycogenolysis physiology
Magnesium analysis
Magnesium metabolism
Magnesium pharmacology
Male
Microsomes, Liver chemistry
Microsomes, Liver drug effects
Mitochondria, Liver chemistry
Mitochondria, Liver drug effects
Obesity chemically induced
Phenylephrine pharmacology
Rats
Rats, Wistar
Secretory Vesicles drug effects
Secretory Vesicles metabolism
Secretory Vesicles pathology
Sodium Glutamate
Subcellular Fractions chemistry
Subcellular Fractions metabolism
Calcium metabolism
Cell Membrane metabolism
Microsomes, Liver metabolism
Mitochondria, Liver metabolism
Obesity metabolism
Obesity pathology
Subjects
Details
- Language :
- English
- ISSN :
- 1532-8600
- Volume :
- 60
- Issue :
- 10
- Database :
- MEDLINE
- Journal :
- Metabolism: clinical and experimental
- Publication Type :
- Academic Journal
- Accession number :
- 21489575
- Full Text :
- https://doi.org/10.1016/j.metabol.2011.02.011