The liver slice system: An in vitro acute toxicity test for assessment of hepatotoxins and their antidotes.

A simple method for rapid and reliable assessment of hepatotoxic agents is described. Liver slices from rats and mice of two age groups were incubated with the test hepatotoxins. Exposure of liver slices from 3-month-old mice to acetaminophen (6.8 mg/ml) resulted in 80% leakage of lactate dehydrogenase into the incubation medium, whereas liver slices from one-day-old mice showed only 12% leakage. Similar results were obtained with rat liver slices. The relative lack of response by livers of newborn rats was also demonstrated with carbon tetrachloride. The in vitro liver slice system has also been used to test the potency of N-acetylcysteine (NAC) as an antidote to acetaminophen toxicity. NAC protected mouse liver slices against acetaminophen toxicity in a dose-dependent manner. Addition of the antidote (10 mm) 20 min following hepatotoxin application reduced enzyme leakage by 75% as compared with the system with acetaminophen only. These findings demonstrate that the liver slice system provides the same type of information about hepatotoxins that is usually obtained by the use of acute in vivo tests on a large number of animals. It can be used for testing potential antidotes against hepatotoxins as well as for demonstration of species and age differences in the toxicity of various substances.