We propose the use of human lymphocyte heme oxygenase 1 (HO1) as a biomarker of response to environmental arsenic exposure. We report the induction of HO1 in human lymphoblastoid cells (LBs) by arsenite in a dose-related manner. HO1 was identified by SDS-PAGE from its molecular weight and from its detection by Western blotting with anti-HO1. HO1 levels in LBs treated with arsenite increased by de novo synthesis as demonstrated by incorporation of 35S-methionine and by inhibition of HO1 synthesis by actinomycin D. The amount of HO1 in LBs was estimated by quantifying Western blots. HO1 was also induced by 10 microM cadmium or mercuric chloride. We suggest that circulating lymphocyte HO1 levels may be useful in assessing the biological activity of arsenic exposure in vivo under properly controlled conditions of simultaneous urinalysis for arsenic, cadmium, and mercury.
Copyright 1998 Academic Press.