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A scanning electron microscope study of the surface features of HeLa S3 suspension-culture cells treated with methylmercury(II)

1979; Academic Press; Volume: 68; Issue: 3 Linguagem: Inglês

10.1016/s0022-5320(79)90161-8

1878-2345

Dieter W. Gruenwedel, John F. Glaser, Richard H. Falk,

Catalytic Processes in Materials Science

HeLa S3 suspension-culture cells were exposed for 12 hr to varied concentrations of CH3Hg(II) and the changes in their surface features that accompany the exposure observed with the aid of a scanning electron microscope. Also investigated in the presence of CH3Hg(II) was the cells' ability to incorporate suitable radioactive-labeled precursors into DNA, RNA, and protein and to prevent trypan blue stain from entering the cell interior. Investigated further was the cells' ability to recover from the effects of the methylmercury treatment once the chemical had been removed from the medium. The results show that suitable concentrations of CH3Hg(II), within a narrow range, inhibit intracellular DNA, RNA, and protein syntheses abruptly, followed as abruptly by a decline in cell viability. At the ultrastructural level, the metabolic inhibition is characterized by extensive cellular “bubbling,” yielding a multitude of cellular shapes and surface structures, by the thinning out and ultimate disappearance of microvilli, and, in cell death, by a seeming collapse of the exoplasmic bubbles due, presumably, to osmotic shock. At CH3Hg(II) concentrations below a certain threshold, the cells recover completely as shown by a rate of precursor incorporation and by surface features that are both indistinguishable from those of the control. In general, the surface features of the cells are considerably more sensitive towards the effects of the methylmercury treatment than are, for instance, intracellular activities such as DNA, RNA, or protein synthesis.