Determination of cellular glutathione:glutathione disulfide ratio in prostate cancer cells by high performance liquid chromatography with electrochemical detection.

A validated method has been developed for the simultaneous measurement of reduced and oxidized glutathione in de-proteinised cellular extracts. This has been used to compare models of malignant and non-malignant human prostate cell lines. Analysis of LNCaP and DU145 cells showed a glutathione to glutathione disulfide ratio of 8:1 and 32:1 respectively, whilst the control cell line, PZ-HPV7 displayed a ratio of 93:1. Results indicate that the more aggressive phenotype displays adaptation to increased oxidative stress via up regulation of glutathione turnover. It was also noted that in the LNCaP and DU145 cell line, glutathione was only responsible for ca. 60% and 79% respectively, of the total cellular reduced thiol; indicating the presence of other biological thiols.