Showing papers by "Maria Rosa Chitolina Schetinger published in 2002"
TL;DR: It is demonstrated that the usual clinical antidepressants are inhibitors of the cholinesterases on human serum and erythrocyte membrane.
80 citations
TL;DR: The results demonstrated that among the elements studied Cd2+ presented the highest toxicity for radish, raising the possibility of using this vegetable as a biomonitor of environmental contamination by these metals.
Abstract: The purpose of the present study was to investigate the in vitro and the in vivo effects of cadmium, zinc, mercury and lead on δ-aminolevulinic acid dehydratase (ALA-D) activity from radish leaves. The in vivo effect of these metals on growth, DNA and protein content was also evaluated. The results demonstrated that among the elements studied Cd2+ presented the highest toxicity for radish. 50% inhibition of ALA-D activity (IC50) in vitro was at 0.39, 2.39, 2.29, and 1.38 mM Cd2+, Zn2+, Hg2+ and Pb2+, respectively. After in vivo exposure Cd2+, Zn2+, Hg2+ and Pb2+ inhibited ALA-D by about 40, 26, 34 and 15%, respectively. Growth was inhibited by about 40, 10, 25, and 5% by Cd2+, Zn2+, Hg2+, and Pb2+, respectively. DNA content was reduced about 35, 30, 20, and 10% for Cd2+, Zn2+, Hg2+, and Pb2+, respectively. The metal concentration in radish leaves exposed to Cd2+, Zn2+, Hg2+, and Pb2+ was 18, 13, 6, and 7 μmol g−1, respectively. The marked ability of radish to accumulate Cd2+ and Zn2+ raises the possibility of using this vegetable as a biomonitor of environmental contamination by these metals.
47 citations
01 Jan 2002
TL;DR: As aluminum in biological systems occurs at trace levels, the analysis of biological matrices will be outlined with respect to aluminum determination considering contamination sources, sample collection and preparation, and methodological procedures.
Abstract: Aluminum is known to affect a wide variety of biological systems. The evolution of life in a highly aluminum-rich biosphere did not result in a known physiological role of aluminum, which is considered a non-essential trace element of low toxicity in living being. In this chapter we review some toxicological and biological aspects of aluminum, as well as the interaction of this element with enzymes that use nucleotides in their reactions. It is assumed that phosphate-bearing biomolecules are elected targets for the biochemical action for aluminum. There is a large number of proteins which require nucleoside phosphates as substrates or are regulated by them. The toxicological mechanisms of aluminum in plants or animals probably involve alterations in the activity of such proteins. As examples of enzymes focus will be placed on NTPases, NTPDases, and kinases. As aluminum in biological systems occurs at trace levels, the analysis of biological matrices will be outlined with respect to aluminum determination considering contamination sources, sample collection and preparation, and methodological procedures.
14 citations