Membrane Transporters as Sites of Action and Routes of Entry for Toxic Metals

Abstract

There is a long history of interest in the interaction of toxic metals with membranes for two reasons. First, it was recognized early on that plasma membranes of cells were important potential targets for metals and that the effects of metals on membrane proteins might provide a basis for understanding the diverse toxic effects of these substances on the nervous system, the kidney, and the GI tract (CLarkson 1972; FOulkes 1986; KInter and PRitchard 1977; OEhme 1978; ROthstein 1970; TEmpleton and CHerian 1983). Equally important historically, however, has been the interest of membrane physiologists in metals, particularly mercurials, as probes of membrane proteins that could be used experimentally to investigate mechanisms of transport and cellular homeostasis (CUrran 1972; FErreira 1978; FRenkel et al. 1975; HIllyard et al. 1979; ROthstein 1970; SChaeffer et al. 1973; SCholtz and ZEiske 1988; SChwartz and FLamenbaum 1976; STirling 1975). A major problem in both areas, however, has been the multiplicity of actions of metals on cell membranes; so that specific sites of action and cause-and-effect relationships have been difficult to sort out. As a result there appears to be a relatively large literature implicating biological membranes as sites of action for metals, but the mechanistic details of the cellular effects that lead to modulation of transport and ultimately to organ dysfunction have not been clearly defined.KeywordsZinc UptakeFrog SkinCopper UptakePhysiological Salt SolutionCadmium UptakeThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.