Serum ornithine carbamyl transferase as a liver response test for exposure to organic solvents.

Ornithine carbamyl transferase (OCT), an enzyme found predominantly in the liver, is released into the bloodstream when liver cells are ruptured. The measurement of serum OCT activity is a convenient, specific, and sensitive assay of liver damage. This test was used to evaluate the effect of several widely used solvents on the livers of guinea pigs. Each solvent was administered intraperitoneally, and 24 hours later serum OCT activity was measured. Many of the solvents tested failed to increase serum OCT activity even at near-lethal doses. Of the thirty-three solvents evaluated, two produced elevations in serum OCT activity at relatively low doses (less than 50 mg/kg), five at moderate doses (50 to 500 mg/kg), and nine at high doses (greater than 500 mg/kg).