Difference between revisions of "Lopez 2009 J Pineal Res"
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|abstract=The role of melatonin in improving mitochondrial respiratory chain activity and increasing ATP production in different experimental conditions has been widely reported. To date, however, the mechanism(s) involved are largely unknown. Using high-resolution respirometry, fluorometry and spectrophotometry we studied the effects of melatonin on normal mitochondrial functions. Mitochondria were recovered from mouse liver cells and incubated in vitro with melatonin at concentrations ranging from 1 nm to 1 mm. Melatonin decreased oxygen consumption concomitantly with its concentration, inhibited any increase in oxygen flux in the presence of an excess of ADP, reduced the membrane potential, and consequently inhibited the production of superoxide anion and hydrogen peroxide. At the same time it maintained the efficiency of oxidative phosphorylation and ATP synthesis while increasing the activity of the respiratory complexes (mainly complexes I, III, and IV). The effects of melatonin appeared to be due to its presence within the mitochondria, since kinetic experiments clearly showed its incorporation into these organelles. Our results support the hypothesis that melatonin, together with hormones such as triiodothyronine, participates in the physiological regulation of mitochondrial homeostasis. | |abstract=The role of melatonin in improving mitochondrial respiratory chain activity and increasing ATP production in different experimental conditions has been widely reported. To date, however, the mechanism(s) involved are largely unknown. Using high-resolution respirometry, fluorometry and spectrophotometry we studied the effects of melatonin on normal mitochondrial functions. Mitochondria were recovered from mouse liver cells and incubated in vitro with melatonin at concentrations ranging from 1 nm to 1 mm. Melatonin decreased oxygen consumption concomitantly with its concentration, inhibited any increase in oxygen flux in the presence of an excess of ADP, reduced the membrane potential, and consequently inhibited the production of superoxide anion and hydrogen peroxide. At the same time it maintained the efficiency of oxidative phosphorylation and ATP synthesis while increasing the activity of the respiratory complexes (mainly complexes I, III, and IV). The effects of melatonin appeared to be due to its presence within the mitochondria, since kinetic experiments clearly showed its incorporation into these organelles. Our results support the hypothesis that melatonin, together with hormones such as triiodothyronine, participates in the physiological regulation of mitochondrial homeostasis. | ||
|keywords=Melatonin, Oxidative phosphorylation, Oxygen consumption, Oxygen radicals, Respiratory chain, Uncoupling | |keywords=Melatonin, Oxidative phosphorylation, Oxygen consumption, Oxygen radicals, Respiratory chain, Uncoupling | ||
|mipnetlab=ES_Granada_Acuna Castroviejo D | |||
|discipline=Mitochondrial Physiology | |discipline=Mitochondrial Physiology | ||
}} | }} | ||
{{Labeling | {{Labeling | ||
|instruments=Oxygraph-2k | |instruments=Oxygraph-2k | ||
|organism= | |organism=Mouse | ||
|tissues=Hepatocyte; Liver | |tissues=Hepatocyte; Liver | ||
|preparations= | |preparations=Isolated Mitochondria | ||
|enzymes= | |enzymes=Complex IV; Cytochrome c Oxidase | ||
|topics=Coupling; Membrane Potential | |||
|topics= | |||
|additional=Spectrophotometry; Spectrofluorimetry | |additional=Spectrophotometry; Spectrofluorimetry | ||
|discipline=Mitochondrial Physiology | |discipline=Mitochondrial Physiology | ||
}} | }} | ||
Revision as of 15:38, 7 September 2011
| López A, García JA, Escames G, Venegas C, Ortiz F, López LC, Acuña Castroviejo D (2009) Melatonin protects the mitochondria from oxidative damage reducing oxygen consumption, membrane potential, and superoxide anion production. J. Pineal Res. 46: 188-198. |
Lopez A, Garcia JA, Escames G, Venegas C, Ortiz F, Lopez LC, Acuna Castroviejo D (2009) J. Pineal Res.
Abstract: The role of melatonin in improving mitochondrial respiratory chain activity and increasing ATP production in different experimental conditions has been widely reported. To date, however, the mechanism(s) involved are largely unknown. Using high-resolution respirometry, fluorometry and spectrophotometry we studied the effects of melatonin on normal mitochondrial functions. Mitochondria were recovered from mouse liver cells and incubated in vitro with melatonin at concentrations ranging from 1 nm to 1 mm. Melatonin decreased oxygen consumption concomitantly with its concentration, inhibited any increase in oxygen flux in the presence of an excess of ADP, reduced the membrane potential, and consequently inhibited the production of superoxide anion and hydrogen peroxide. At the same time it maintained the efficiency of oxidative phosphorylation and ATP synthesis while increasing the activity of the respiratory complexes (mainly complexes I, III, and IV). The effects of melatonin appeared to be due to its presence within the mitochondria, since kinetic experiments clearly showed its incorporation into these organelles. Our results support the hypothesis that melatonin, together with hormones such as triiodothyronine, participates in the physiological regulation of mitochondrial homeostasis. • Keywords: Melatonin, Oxidative phosphorylation, Oxygen consumption, Oxygen radicals, Respiratory chain, Uncoupling
• O2k-Network Lab: ES_Granada_Acuna Castroviejo D
Labels:
Organism: Mouse
Tissue;cell: Hepatocyte; Liver"Hepatocyte; Liver" is not in the list (Heart, Skeletal muscle, Nervous system, Liver, Kidney, Lung;gill, Islet cell;pancreas;thymus, Endothelial;epithelial;mesothelial cell, Blood cells, Fat, ...) of allowed values for the "Tissue and cell" property.
Preparation: Isolated Mitochondria"Isolated Mitochondria" is not in the list (Intact organism, Intact organ, Permeabilized cells, Permeabilized tissue, Homogenate, Isolated mitochondria, SMP, Chloroplasts, Enzyme, Oxidase;biochemical oxidation, ...) of allowed values for the "Preparation" property.
Enzyme: Complex IV; Cytochrome c Oxidase"Complex IV; Cytochrome c Oxidase" is not in the list (Adenine nucleotide translocase, Complex I, Complex II;succinate dehydrogenase, Complex III, Complex IV;cytochrome c oxidase, Complex V;ATP synthase, Inner mt-membrane transporter, Marker enzyme, Supercomplex, TCA cycle and matrix dehydrogenases, ...) of allowed values for the "Enzyme" property.
Regulation: Coupling; Membrane Potential"Coupling; Membrane Potential" is not in the list (Aerobic glycolysis, ADP, ATP, ATP production, AMP, Calcium, Coupling efficiency;uncoupling, Cyt c, Flux control, Inhibitor, ...) of allowed values for the "Respiration and regulation" property.
HRR: Oxygraph-2k
Spectrophotometry; Spectrofluorimetry
