Scheibye-Knudsen 2009 Eur J Appl Physiol
| Scheibye-Knudsen M, Quistorff B (2009) Regulation of mitochondrial respiration by inorganic phosphate: comparing permeabilized muscle fibers and isolated mitochondria prepared from type-1 and type-2 rat skeletal muscle. Eur J Appl Physiol 105:279-87. |
Scheibye-Knudsen M, Quistorff B (2009) Eur J Appl Physiol
Abstract: ADP is generally accepted as a key regulator of oxygen consumption both in isolated mitochondria and in permeabilized fibers from skeletal muscle. The present study explored inorganic phosphate in a similar regulatory role. Saponin permeabilized fibers and isolated mitochondria from type-I and type-II muscle from male Wistar rats were prepared. Respiration was measured while the medium Pi concentration was gradually increased. The apparent Km values for Pi were 607 Β± 17 Β΅M and 405 Β± 15 ΞΌM (P < 0.0001) for type-I and type-II fibers, respectively. For isolated mitochondria the values were significantly lower than type-1 permeabilized fibers, 338 Β± 130 ΞΌM and 235 Β± 30 ΞΌM (P < 0.05), but not different with respect to fiber type. The reason for this difference in Km values in the permeabilized muscle is unknown, but a similar pattern has been observed for K m of ADP. Our data indicate that phosphate may play a role in regulation of oxygen consumption in vitro and in vivo. β’ Keywords: Mitochondrial respiration, Permeabilized muscle, Inorganic phosphate, Striated muscle, Oxygen consumption, Oxidative phosphorylation
β’ O2k-Network Lab: DK Copenhagen Quistorff B
Labels:
Organism: Rat
Tissue;cell: Skeletal muscle
Preparation: Permeabilized tissue, Isolated mitochondria
Regulation: Phosphate Coupling state: OXPHOS
HRR: Oxygraph-2k
