Analysis of hepatic reduced glutathione, cysteine and homocysteine by cation-exchange high-performance liquid chromatography with electrochemical detection.

Abstract

A high-performance liquid chromatographic method employing a mercury-based electrochemical detector and a cation-exchange column is described for the simultaneous measurement of reduced glutathione, cysteine, and homocysteine in liver homogenates. Sample preparation involves precipitation of protein with perchloric acid, removal of perchlorate by precipitation as its potassium salt and dilution with mobile phase. Mercaptoethylglycine is used as the internal standard. Using this procedure, the sum of the individual hepatic thiols agreed well with the total thiols determined with Ellman's reagent. Comparisons were made with (a) control rats, (b) rats depleted of hepatic thiols by pargyline pretreatment, and (c) rats administered L-cysteine.