Immunochemical quantitation of 3-(cystein-S-yl)acetaminophen adducts in serum and liver proteins of acetaminophen-treated mice

Using a recently developed enzyme-linked immunosorbent assay specific for 3-(cystein-S-yl)acetaminophen adducts we have quantitated the formation of these specific adducts in liver and serum protein of B6C3F1 male mice dosed with acetaminophen. Administration of acetaminophen at doses of 50, 100, 200, 300, 400 and 500 mg/kg to mice resulted in evidence of hepatotoxicity (increase in serum levels of alanine aminotransferase and aspartate aminotransferase) at 4 hr in the 300, 400 and 500 mg/kg treatment groups only. The formation of 3-(cystein-S-yl)acetaminophen adducts in liver protein was not observed in the groups receiving 50, 100 and 200 mg/kg doses, but was observed in the groups receiving doses above 300 mg/kg of acetaminophen. Greater levels of adduct formation were observed at the higher doses. 3-(Cystein-S-yl)acetaminophen protein adducts were also observed in serum of mice receiving hepatotoxic doses of acetaminophen. After a 400 mg/kg dose of acetaminophen, 3-(cystein-S-yl)acetaminophen adducts in the liver protein reached peak levels 2 hr after dosing. By 12 hr the levels decreased to approximately 10% of the peak level. In contrast, 3-(cystein-S-yl)acetaminophen adducts in serum protein were delayed, reaching a sustained peak 6 to 12 hr after dosing. The dose-response correlation between the appearance of serum aminotransferases and 3-(cystein-S-yl)acetaminophen adducts in serum protein and the temporal correlation between the decrease in 3-(cystein-S-yl)acetaminophen adducts in liver protein and the appearance of adducts in serum protein are consistent with a hepatic origin of the adducts detected in serum protein.(ABSTRACT TRUNCATED AT 250 WORDS)