Effect of chloroform on the activities of liver enzymes in rats.

Rats were dosed once, 5 times or 10 times with chloroform (0.5-50 mg/kg) and the liver enzyme activities were determined. Chloroform induced much change in the 24 enzymes investigated but caused only minimal liver enlargement. The main enzymic changes were: stimulation of glycolysis and oxidative phosphorylation, increased breakdown of protein and nucleic acids, hexose phosphate shunt activity was reduced leading to a shortage of NADPH in the cell, adrenal medullary and cortical secretion were stimulated. These results show that ingestion of chloroform even in small amounts causes distinct changes in liver cell metabolism as indicated by enzyme activities. Some of the changes are similar to, but others differ from, those seen with larger and anaesthetic doses. In most cases a transition between these 2 types of effects can be seen.