Enalapril (MK421) activation in man: importance of liver status

The in vitro conversion of enalapril (MK421) to enalaprilic acid (MK422) in human autopsy tissues was examined. MK422 was measured by radioimmunoassay. Human cadaver liver was the only tissue in which significant conversion was demonstrated. The esterase activity was stable after post mortem. Autopsy liver tissues from patients with elevated ante mortem liver function tests were found to have a reduced rate of deesterification.