Cadmium is a heavy metal that is toxic for living organisms even at lowconcentrations. The presence in the environment of this metal has grown because of itslarge employment in some industrial and agricultural activities. Although heavy metalsare terrestrially produced, they flow into the sea through effluents and sewage or aredirectly discharged from industries placed on the seawater front. In addition to its releaseinto costal waters, cadmium fallout, following atmospheric events, contributes to thepollution of marine ecosystems. It should be considered that cadmium concentrationsdetermined in the field vary widely according to different seawater latitudes and depthsand can be strongly influenced by freshwater discharges from heavily polluted rivers.Cadmium does not have any biological role and, since it cannot be degraded, it isirreversibly accumulated into cells, interacting with cellular components and moleculartargets. Experimental evidence suggests that the metal crosses the plasma membrane as abivalent ion, exerting an agonistic role against calcium ionic channels. The metal hasbeen associated with blockage of oxidative phosphorylation, glutathione depletion andantioxidant enzymatic activity inhibition, production of ROS, DNA damage, andinhibition of relative repair mechanisms, a general reduction of protein synthesis coupledwith an increase in stress proteins. For many years, the effects of various pollutants onaquatic invertebrates have been studied. Most of these studies examined thedevelopmental defects due to the presence, in rearing media, of a specific toxicant such ascadmium. Considering the capacity of sea urchin embryos and larvae to accumulatecontaminants during development, this developmental model offers an excellentopportunity to investigate the possible adaptive response of cells exposed to cadmiumduring differentiation. In this review, we will examine the cellular, biochemical andmolecular effects produced by cadmium ions on Paracentrotus lividus sea urchinembryos. Specifically we will consider the following: i) Cd2+ accumulation duringembryonic development; ii) stress protein synthesis and accumulation (HSPs) andmetallothioneins; and iii) induction of apoptosis and related pathways.
|Titolo della pubblicazione ospite||Cadmium in the Environment|
|Numero di pagine||30|
|Stato di pubblicazione||Published - 2009|
All Science Journal Classification (ASJC) codes