Abstract
Biology is rich in claims that reactive oxygen and nitrogen species are involved
in every biological process and disease. However, many quantitative aspects of
redox biology remain elusive. The important quantitative parameters you need to
address the feasibility of redox reactions in vivo are: rate of formation and
consumption of a reactive oxygen and nitrogen species, half-life, diffusibility
and membrane permeability. In the first part, we explain the basic chemical
kinetics concepts and algebraic equations required to perform “street
fighting” quantitative analysis. In the second part, we provide key
numbers to help thinking about sizes, concentrations, rates and other important
quantities that describe the major oxidants (superoxide, hydrogen peroxide,
nitric oxide) and antioxidants (vitamin C, vitamin E, glutathione). In the third
part, we present the quantitative effect of exercise on superoxide, hydrogen
peroxide and nitric oxide concentration in mitochondria and whole muscle and
calculate how much hydrogen peroxide concentration needs to increase to
transduce signalling. By taking into consideration the quantitative aspects of
redox biology we can: i) refine the broad understanding of this research area,
ii) design better future studies and facilitate comparisons among studies, and
iii) define more efficiently the “borders” between cellular
signaling and stress.
Key words
free radicals - oxidative stress - oxidation - oxidative damage - skeletal muscle - training adaptations
