Cell functions progressively decrease as a person ages. The mitochondrial activity also leads to age-related diseases. Biomedical experts recognize the importance of these life processes. They associate aging and diseases with dysfunction in adenosine triphosphate (ATP). Central metabolic pathways, radical production, and Ca2+ homeostasis also have an impact. This study looks at mitochondrial mechanisms that regulate superoxide (O2) and hydrogen peroxide (H2O2) formation.

The researchers isolated the skeletal muscle mitochondria to measure the mechanisms. The capacity of different sites to produce superoxide and hydrogen peroxide was also an element of the study. Different sites were essential to measure the rate of production. The researchers added the crucial measurement of native rates in the absence of respiratory chain inhibitors. The researchers assessed the contributions of specific sites in situ and in vivo for further clarity.

The results show that different sites have different production capacities. The maximum capacities of sites are in complexes I, II, and III. They exceed the native rates as do those in several associated redox enzymes. The native rates and relative site importance in the cell depend on the oxidized substrate. The sites like IQ, IIF, GPDH, IF, and IIIQo are equally significant with particular substrates. 

The rate measurement techniques in each site are practical and useful. They can get applied to cell cultures and in vivo studies in the future.

Ref: https://onlinelibrary.wiley.com/doi/10.1111/bjd.12208