Abstract

The embryotoxic effect of intermediate frequency (IF) magnetic field (MF) was evaluated using murine embryonic stem (ES) cells and fibroblast cells based on the embryonic stem cell test (EST). The cells were exposed to 21 kHz IF–MF up to magnetic flux density of 3.9 mT during the cell proliferation process (7 days) or the cell differentiation process (10 days) during which an embryonic body differentiated into myocardial cells. As a result, there was no significant difference in the cell proliferation between sham- and IF–MF-exposed cells for both ES and fibroblast cells. Similarly, the ratio of the number of ES-derived cell aggregates differentiated to myocardial cells to total number of cell aggregates was not changed by IF–MF exposure. In addition, the expressions of a cardiomyocytes-specific gene, Myl2, and an early developmental gene, Hba-x, in the exposed cell aggregate were not altered. Since the magnetic flux density adopted in this study is much higher than that generated by an inverter of the electrical railway, an induction heating (IH) cooktop, etc . in our daily lives, these results suggested that IF–MF in which the public is exposed to in general living environment would not have embryotoxic effect.

Abstract

Heavy metals incidence in the aquatic environment and its accumulation in fish are under constant review. Gilthead seabream (Sparus aurata ) specimens were exposed for two weeks to sediments highly concentrated in metals, collected at the Portman Bay (Murcia, Spain). The metals bioaccumulation was tested in liver, muscle and skin. The potential of the sediment exposure to induce variation of the stress biomarkers genes was conducted in liver and skin. Results revealed that sediments were highly contaminated with metals. However, following 2 weeks exposure to the sediments, Cd accumulates only in liver. Interestingly, the expression of the genes mta, hsp 70 and hsp 90 were significantly down-regulated in skin. Nevertheless, cyp1a1 gene was up-regulated only in liver. Results uphold that the stress response magnitude was organ-dependent and the skin was the most responsive tissue to metal stress conditions. These results suggest that skin should be considered as target organ for biomarkers analysis in fishes.