Steatohepatitis-inducing drugs cause mitochondrial dysfunction and lipid peroxidation in rat hepatocytes.

BACKGROUND & AIMS: 4,4'-Diethylaminoethoxyhexestrol (DEAEH), amiodarone, and perhexiline cause steatohepatitis in humans. The mechanisms of these effects are unknown for DEAEH and have not been completely elucidated for amiodarone and perhexiline. The aim of this study was to determine these mechanisms.

METHODS

Rat liver mitochondria, cultured rat hepatocytes, or rats were treated with these drugs, and the effects on mitochondrial respiration, beta-oxidation, reactive oxygen species formation, and lipid peroxidation were determined.

RESULTS

DEAEH accumulated in mitochondria and inhibited carnitine palmitoyl transferase I and acyl-coenzyme A dehydrogenases; it decreased beta-oxidation and caused lipid deposits in hepatocytes. DEAEH also inhibited mitochondrial respiration and decreased adenosine triphosphate (ATP) levels in hepatocytes. DEAEH, amiodarone, and perhexiline augmented the mitochondrial formation of reactive oxygen species and caused lipid peroxidation in rats.

CONCLUSIONS

Like amiodarone and perhexiline, DEAEH accumulates in mitochondria, where it inhibits both beta-oxidation (causing steatosis) and respiration. Inhibition of respiration decreases ATP and also increases the mitochondrial formation of reactive oxygen species. The latter oxidize fat deposits, causing lipid peroxidation. We suggest that ATP depletion and lipid peroxidation may cause cell death and that lipid peroxidation products may account, in part, for other steatohepatitis lesions.