Tomar 2022 Biochim Biophys Acta Bioenerg

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Publications in the MiPMap
Tomar N, Zhang X, Kandel SM, Sadri S, Yang C, Liang M, Audi SH, Cowley AW Jr, Dash RK (2022) Substrate-dependent differential regulation of mitochondrial bioenergetics in the heart and kidney cortex and outer medulla. https://doi.org/10.1016/j.bbabio.2021.148518

ยป Biochim Biophys Acta Bioenerg 1863:148518. PMID: 34864090 Open Access

Tomar N, Zhang X, Kandel SM, Sadri S, Yang C, Liang M, Audi SH, Cowley AW Jr, Dash RK (2022) Biochim Biophys Acta Bioenerg

Abstract: The kinetics and efficiency of mitochondrial oxidative phosphorylation (OxPhos) can depend on the choice of respiratory substrates. Furthermore, potential differences in this substrate dependency among different tissues are not well-understood. Here, we determined the effects of different substrates on the kinetics and efficiency of OxPhos in isolated mitochondria from the heart and kidney cortex and outer medulla (OM) of Sprague-Dawley rats. The substrates were pyruvate+malate, glutamate+malate, palmitoyl-carnitine+malate, alpha-ketoglutarate+malate, and succinateยฑrotenone at saturating concentrations. The kinetics of OxPhos were interrogated by measuring mitochondrial bioenergetics under different ADP perturbations. Results show that the kinetics and efficiency of OxPhos are highly dependent on the substrates used, and this dependency is distinctly different between heart and kidney. Heart mitochondria showed higher respiratory rates and OxPhos efficiencies for all substrates in comparison to kidney mitochondria. Cortex mitochondria respiratory rates were higher than OM mitochondria, but OM mitochondria OxPhos efficiencies were higher than cortex mitochondria. State 3 respiration was low in heart mitochondria with succinate but increased significantly in the presence of rotenone, unlike kidney mitochondria. Similar differences were observed in mitochondrial membrane potential. Differences in H2O2 emission in the presence of succinateยฑrotenone were observed in heart mitochondria and to a lesser extent in OM mitochondria, but not in cortex mitochondria. Bioenergetics and H2O2 emission data with succinateยฑrotenone indicate that oxaloacetate accumulation and reverse electron transfer may play a more prominent regulatory role in heart mitochondria than kidney mitochondria. These studies provide novel quantitative data demonstrating that the choice of respiratory substrates affects mitochondrial responses in a tissue-specific manner.

โ€ข Bioblast editor: Gnaiger E โ€ข O2k-Network Lab: US WI Milwaukee Dash RK

On terminology

ยป Mitochondrial states and rates - terminology beyond MitoEAGLE 2020
For harmonization of terminology on respiratory states and rates, see

Labels:






Outdated terminology 


Labels: MiParea: Respiration 

Stress:Oxidative stress;RONS  Organism: Rat  Tissue;cell: Heart, Kidney  Preparation: Isolated mitochondria 

Regulation: ADP, Inhibitor, mt-Membrane potential  Coupling state: LEAK, OXPHOS, ET  Pathway: F, N, S  HRR: Oxygraph-2k 


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