Differential expression of metallothionein-1 and cytochrome p450-2a5 (cyp2a5) in mice in response to lead acetate exposure and industrial effluents in Ibadan, Nigeria

Abstract

Metallothionein-1 ( MT-1), cytochrome P450-2A ( CYP2a) and other genes are involved in the detoxification of xenobiotics such as heavy metals and toxins. Changes in their expression precede overt toxic effects and can serve as a marker for exposure to pollutants. We used a mouse experimental system and quantitative reverse transcription polymerase chain reaction to determine changes in gene expression and the direction of change, in response to exposure to lead acetate (LA) and waste water (WW) from an industrial area in Ibadan. MT-1 and CYP2a5 genes were quickly and highly induced at different exposure periods and concentrations. MT-1 was mostly downregulated by the LA exposure, but upregulated by several folds on exposure to WW. CYP2a5 expression was mostly downregulated with LA exposure. The optimum expression of MT-1 and CYP2a5 genes induced by both LA and WW was at 48 h. We conclude that rapid assays to determine the direction of change in the expression of MT-1 and CYP2a5 could be a fast and reliable method in developing countries for screening humans exposed to pollutants from industrial waste.