Young Scientists Award Lecture 1977: An Investigation into the Value of Some Clinical Biochemical Tests in the Detection of Minimal Changes in Liver Morphology and Function in the Rat

Abstract

Minimal liver damage was induced in groups of rats by the administration of three toxicants, viz. carbon tetrachloride, sodium phenobarbitone and orotic acid. Serial blood samples were taken from the animals during the course of the experiment and the plasma levels of a number of enzymes, substrates and metabolites were measured. Liver and kidney samples were also taken at appropriate times after dosing and examined histologically for evidence of drug induced damage. The results of the experiment show that

• I) no single test gave unequivocal evidence of liver damage for all three compounds,

• II) the conventional liver function tests, alanine transaminase, aspartate transaminase, and alkaline phosphatase, whose plasma activities are usually reported in toxicity studies, were not the most sensitive indicators of the minimal liver cell damage caused by the drugs used in this experiment,

• III) knowledge of the intracellular location of the diagnostic enzyme makes it possible to describe, at least in part, the nature of the changes within the liver,

• IV) measurement of plasma cholesterol and triglyceride levels can provide information about disruption in lipid metabolism,

• V) the times at which blood samples are taken are most important if transient drug effects on the liver are to be detected.