Effects of pyridoxal 5'-phosphate on plasma alanine aminotransferase determinations in toxicological studies.

Alanine aminotransferase activities (ALT) were measured in rat plasma samples with three different reagent formulations. The inclusion of pyridoxal 5'-phosphate in the reagent produced higher ALT values, and altered the statistical relationships between control and treatment groups in three studies where plasma ALT values were reduced by xenobiotics.