ABSTRACT
A literature survey was made of the interactions--in the organism--between some food contaminating elements (mercury, tin, nickel, selenium, fluorine, aluminium) and iron, zinc and copper. The harmful elements may disturb the mineral metabolism already at the stage of intestinal absorption. Moreover, they bring about changes in microelement distribution in the tissues and cells. On account of their approximately similar chemical structure, they compete for the sites of binding to some proteins, including enzymic ones. In this respect a special role is played by ++metallothionein, a protein with the ability of regulating free metal contents in the tissues and thus possibly displaying some detoxifying properties. Many mechanisms and relationships determining the interactions between the surveyed food contaminants and iron, zinc and copper remain, however, not elucidated.
Subject(s)
Copper/pharmacology , Fluorine/toxicity , Food Contamination , Iron/pharmacology , Metals/toxicity , Selenium/toxicity , Zinc/pharmacology , Aluminum/antagonists & inhibitors , Aluminum/pharmacokinetics , Aluminum/toxicity , Animals , Copper/metabolism , Drug Interactions , Fluorine/antagonists & inhibitors , Fluorine/pharmacokinetics , Humans , Iron/metabolism , Mercury/antagonists & inhibitors , Mercury/pharmacokinetics , Mercury/toxicity , Metals/antagonists & inhibitors , Metals/pharmacokinetics , Nickel/antagonists & inhibitors , Nickel/pharmacokinetics , Nickel/toxicity , Rats , Selenium/antagonists & inhibitors , Selenium/pharmacokinetics , Tin/antagonists & inhibitors , Tin/pharmacokinetics , Tin/toxicity , Zinc/metabolismABSTRACT
The protective effect of selenium (Se) on the inhibition of erythrocyte 5-aminolevulinate dehydratase (ALAD) activity by tin (Sn) was examined in mice. When mice were intraperitoneally (i.p.) administered 10 mumol/kg of stannous chloride, the activity of erythrocyte ALAD decreased to 35% of control. When more than an equimolar dose of sodium selenite was injected i.p. simultaneously with Sn, the ALAD activity was completely protected. Mortalities and weight gains of mice treated with Se were also reduced when Sn was administered simultaneously.
Subject(s)
Erythrocytes/enzymology , Porphobilinogen Synthase/antagonists & inhibitors , Selenium/pharmacology , Tin/antagonists & inhibitors , Animals , Body Weight/drug effects , Dose-Response Relationship, Drug , Male , Mice , Mice, Inbred ICR , Porphobilinogen Synthase/blood , Time Factors , Tin/pharmacologyABSTRACT
1. The binding of triethyltin to rat liver mitochondria is unaffected by the nature of the predominant anion in the incubation medium. 2. With chloride, bromide or iodide as the predominant anion, ATP synthesis linked to the oxidation of pyruvate or succinate and ATP hydrolysis stimulated by 2,4-dinitrophenol are much more sensitive to triethyltin than they are when nitrate or isethionate is the predominant anion. 3. When nitrate or isethionate is the predominant anion, oxygen uptake stimulated by 2,4-dinitrophenol is not inhibited by triethyltin. 4. In the presence of nitrate or isethionate anions, inhibition of ATP synthesis is directly related to the binding of triethyltin to mitochondria. 5. The relationship of the above effects to the anion-hydroxide ion exchange mediated by triethyltin and the relevance of this to published arrangements for coupling of electron transport to ATP synthesis are discussed.
