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Costa 1997 Am J Physiol Cell Physiol

From Bioblast
Publications in the MiPMap
Costa LE, Mรฉndez G, Boveris A (1997) Oxygen dependence of mitochondrial function measured by high-resolution respirometry in long-term hypoxic rats. Am J Physiol Cell Physiol 273:C852-8.

ยป PMID: 9316405

Costa LE, Mendez G, Boveris A (1997) Am J Physiol Cell Physiol

Abstract: Respiration and oxidative phosphorylation were investigated in tightly coupled mitochondria isolated from liver and heart of rats submitted to a simulated altitude of 4,400 m for 14-15 mo and their corresponding controls at sea level. High-resolution respirometry was utilized to determine the apparent Michaelis-Menten constant for ADP and O2 (K(m)-ADP and K(m)-O2, respectively), the latter under active and resting states of mitochondrial respiration. The K(m)-O2 in mitochondria isolated from normoxic rats was higher for active (State 3) than for resting (State 4) respiration; the values decreased from 1.5 and 1.7 to 0.25 and 0.30 microM in heart and liver mitochondria, respectively. The K(m)-O2 values found in the active state suggest a role for the normally occurring intracellular pO2 range reported in the literature in the regulation of cellular respiration. No changes were found in the ADP or O2 dependence of respiration in the mitochondria isolated from long-term acclimatized rats compared with their controls, indicating that the intrinsic properties and the efficiency of mitochondria do not change as a consequence of adaptation to hypoxia.


โ€ข O2k-Network Lab: AR Buenos Aires Boveris A


Labels: MiParea: Respiration 


Organism: Rat  Tissue;cell: Heart, Liver  Preparation: Isolated mitochondria 

Regulation: ADP, Oxygen kinetics  Coupling state: LEAK, OXPHOS  Pathway:HRR: Oxygraph-2k 


Discussion