Biological effects of contaminants: Quantification of δ-aminolevulinic acid dehydratase (ALA-D) activity in fish blood.

Abstract

This document describes a colorimetric method to quantify the enzyme δ-aminolevulinic acid dehydratase (ALA-D) in fish blood. ALA-D is an enzyme in the heme synthesis pathway. The activity of the enzyme is inhibited by lead (Pb) and it has, therefore, been used as a biomarker for lead exposure and effects in mammals, birds, and fish. This paper describes optimal conditions for the kinetic determination of ALA-D activity in fish blood, standardized to protein content.