Měření

Extracellular concentrations of GSH

• Relatively low 2–20 µmol/L in plasma [1]

Total glutathione

• GSH + 2GSSG concentration

Koncentrace glutathionu v buňce

• Animal cells 0.5–10 mmol/L
• 85–90% - cytosol
• Remainder in organelles ( mitochondria, nuclear matrix, and peroxisomes,...)

Koncentrace glutathionu v buňce

• Animal cells 0.5–10 mmol/L
• 85–90% - cytosol
• Remainder in organelles ( mitochondria, nuclear matrix, and peroxisomes,...)

Moč

• Increase in urinary excretion of 5-oxoproline = intermediate of the gamma-glutamyl cycle
• Useful indicator of reduced availability of cysteine and/or glycine for GSH synthesis in vivo [1]

Obrat GSH

• In healthy adult humans
• Endogenous disappearance rate (utilization rate) of GSH is 25 µmol/(kg · h)
• Accounts for 65% of whole body cysteine flux [38.3 µmol/(kg · h)]
• Finding supports the view that GSH acts as a major transport form of cysteine in the body
• Among extrahepatic cells, the erythrocyte
• Has a relatively high turnover rate for GSH

• Dietary cysteine intake [9 µmol/(kg · h)] in healthy adult humans
• Estimated that most of the cysteine used for endogenous GSH synthesis is derived from
• Intracellular protein degradation and/or endogenous synthesis

• For example, the whole-blood fractional synthesis rate of GSH in healthy adult subjects is 65%/d
• All the GSH is completely replaced in 1.5 d
• This value is equivalent to 3 µmol/(kg · h)
• Whole blood (mainly erythrocytes) may contribute up to 10% of whole-body GSH synthesis in humans

Orgány a GCS

• Source of glutamate for GCS differs between the small intestine and kidney
• Diet vs. arterial blood

[GSH]:[GSSG] ratio

• Often used as an indicator of the cellular redox state
• GSH/GSSG is the major redox couple that determines the antioxidative capacity of cells
• Its value can be affected by other redox couples, including
• NADPH/NADP+
• Thioredoxinred/thioredoxinox

Žluč

• Bile acid may contain up to 10 mmol/L GSH