CYTOMETRIC PROFILES OF BONE-MARROW AND SPLEEN LYMPHOID-CELLS AFTER MERCURY EXPOSURE IN MICE

The potential immunotoxic effects of mercury chloride on murine bone m arrow (bm) cell subpopulations, including analysis of maturation patte rns for B-cells, were evaluated by flow cytometric analysis. CD-1 outb red mice were exposed for 28 days to relatively low doses of 25 - 100 ppm HgCl2 in drinking water and the mercury-related functional cellula r changes were validated in a macrophage phagocytosis assay. Lymphocyt e subsets from the bone marrow population were stained with PNA lectin and a panel of monoclonal antibodies against cell surface antigens. T he incidence of subset-specific staining was also monitored in spleens and thymuses. A dose-effect correlation was noted for the mercury-rel ated activation of macrophage phagocytosis. Subchronic exposure to mer curic chloride resulted in a transient (7 - 14 day) decrease of the ly mphoid/total bm cell ratio and affected the incidence of splenic T-cel l subsets, however, without a clear dose-response correlation. The B-c ell population in spleen and maturation patterns of B-cells in bm appe ared to be unaffected by the mercury exposure. Overall, cytometric ana lysis of lymphoid cell subsets in murine bone marrow revealed transien t and subset-non-specific cell fluctuations after subchronic exposure to inorganic mercury.