Gas chromatographic analysis of free and bound malonaldehyde in rat liver homogenates.

A gas chromatographic method for the measurement of free and bound malonaldehyde (MA) in rat liver homogenate was developed to investigate biological damage caused by lipid peroxidation. Free MA was derivatized 1-methylpyrazole (1-MP), which was subsequently analyzed by capillary gas chromatography (GC). Bound forms of MA were determined by first hydrolyzing samples in acetic acid, then measuring the free MA as 1-MP. Bound MA in rat liver was released within 15 min by acid hydrolysis. A slight increase in bound MA levels in rat liver was observed 1 hr after CCl4 treatment, with bound MA then returning to control levels. Free MA levels and thiobarbituric acid assay (TBA) values did not show appreciable changes over a 24-hr period after CCl4 administration. However, the TBA values were approximately ten times the MA values in most samples.