where E stands for the enrichment expressed as MPE. The nominator (product) of this equation represents the hourly increase in [U-13 C]glycine bound to GSH, as calculated from the increase in enrichment between 6 and 8 h of infusion. The denominator (precursor) represents the intraerythrocytic U-13 C enrichment of free glycine at isotopic steady state.
Subsequently, the intravascular ASRGSH, which represents the absolute amount of GSH that is produced per unit of time (mg/(kg·day)), can be calculated using the following equation: