Presence of epoxide hydrolase and glutathione S-transferase in human pulmonary alveolar macrophages.

Pulmonary alveolar macrophages (PAMs) were obtained from 11 patients by bronchoalveolar lavage. Epoxide hydrolase and glutathione S-transferase in sonicated PAMs were measured using benzo(a)pyrene-4,5-oxide as the substrate. The activity of epoxide hydrolase was 0.24 +/- 0.10 nmol/min/mg protein (mean +/- SD), and of glutathione S-transferase 0.22 +/- 0.12 nmol/min/mg protein. There was a significant difference in enzyme activities in the PAMs from smokers and non-smokers. Epoxides may be metabolized in PAMs.