Novel assay for glutathione reductase activity by high-performance liquid chromatography with electrochemical...

A new method was devised for the direct measurement of glutathione reductase activity in crude tissue samples using high-performance liquid chromatography and electrochemical detection with a mercury/gold electrode. This assay depends on the high sensitivity of the electrode to detect SH groups produced from a substrate, oxidized glutathione, the interference of which can be excluded by setting the oxidation voltage as low as 100 mV. The sensitivity was high enough to detect the activity in crude samples containing less than 1 microg of protein. This method proved to be sensitive and simple for the measurement of this biologically important reductant activity without the need for a further purification procedure.