FIGURE 3.

Illustration of how the intracellular redox state is communicated to the blood stream via common metabolites. The thiol ratio is reflected mainly in the cysteine to cystine ratio but also in the GSH/GSSG ratio. The mitochondrial pyridine nucleotide redox state is reflected in the β/A ratio and regulated mainly by liver mitochondria. The cytosolic pyridine nucleotide redox state is reflected in the L/P ratio and regulated mainly by muscle. All of these redox indicators are readily transported into and out of cells. Bold type indicates reaction is mainly regulated in that tissue.