Role of neutrophils in hepatotoxicity induced by oral acetaminophen administration in rats

Acetaminophen (APAP) is a common analgesic and antipyretic compound which, when administered in high doses, has been associated with significant morbidity and mortality, secondary to hepatic toxicity. To date, the mechanism(s) whereby APAP induces liver injury remains to be delineated. This study investigated the potential role of neutrophils as contributors to liver injury in rats administered sublethal doses of APAP. Oral APAP administration (650 mg/kg) was associated with increases in serum alanine transaminase (ALT) levels indicating biochemical evidence of significant liver damage. Furthermore, histological analyses verified significant hepatocellular necrosis as well as enhanced myeloperoxidase staining in these liver specimens. However, if animals were pretreated with antineutrophil sera prior to APAP administration, neutrophil counts remained depressed, ALT levels were significantly decreased, and the degree of liver injury was attenuated on a histological level. Taken together these data suggest that neutrophils mediate, at least in part, the hepatotoxic effects of oral acetaminophen administration in rats.