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(26-10) Effects of blood relevant concentration of metals on human immune cells competence. Fournier, Michel*,1, Fortier, Marlène1, Omara, Félix1, Bernier, Jacques1, Kouassi, Edouard1, 1 Human Health Research Center, INRS-Institut Armand-Frappier, Pointe-Claire, Québec, Canada ABSTRACT- Among environmental contaminants recognized for their toxicity and worldwide distribution, heavy metals are certainly of first concern. Studies indicate that metals can elicit a number of immunomodulatory effects leading ultimately to an enhanced susceptibility to microbial agents and to the appearance of neoplastic diseases and autoimmune phenomena. However, experiments are often conducted at levels higher than environmental levels, or at concentrations higher than that found in human blood. This project was designed to assess toxicity of these metals and determination of risks associated with human exposure at physiologically relevant human blood levels. Blood from 15 healthy human volunteers (40 + 10 years of age) have been collected by venipuncture into heparinized tubes, and peripheral blood leukocytes (PBLs) were isolated. Cells were exposed for 72 hours to individual metals (Cd, Hg or Pb) and mixtures of metals (Pb + Hg, Pb + Cd, Cd + Hg and Pb + Hg + Cd) at physiologically relevant reported human blood levelsand effects on cell viability was recorded. For Hg, further study were performed by assessing effects of exposure on: blastic transformation, phagocytosis, peroxyde production and NK activity were determined. At the highest relevant dose, suppression of all these endpoints were noted were. NK activity express an higher sensitivity, being supressed by lower doses of Hg. These results demonstrated that relevant concentration of metals may be of concern. Supported by the Canadian Toxic Research Substances Key words: Heavy metals, immunotoxicology |
