Interaction of zinc in pancreatic β-cells with reduced form of gluthation as possible cause of its protective activity

Abstract

It is known that Zinc which is contains in pancreatic β-cells of take participation in formation of deposited storage form of insulin in cells. It is known now a 18 Diabetogenic zinc binding β-cytotoxic chemicals (DZC) which in β-cells formed toxic chelat complexes that result destruction and death of β-cells within 15–30 min. and developing of diabetes. Among 18 DZC 17 of them are belong to derivatives of 8-oxyquinolin which are a components of more than 10 pharmaceutical drugs. It is known also that administration of amino acid a Reduced form of Glutathione completely protect pancreatic B-cells of destruction and prevent developing of diabetes caused by DZC. It is supposed that this property of Glutathione is determined by its ability to block of zinc in B-cells and to prevent interaction of it with DZC. Authors using of sensitive and high specific histochemical methods established that only Reduced form of Glutathione contains of SH-radical in structure of molecule blocked zinc ions in β-cells and protect of its from destruction caused by DZC contrary to Oxidized form of Glutathione not contains of SH-radical, not blocking of zinc ions in β-cells and not protect formation of zinc-DZC complexes in β-cells accompanied by death of cells. Authors suppose that in process of formation of toxic complexes as zinc-DZC atom of zinc is fixed between atom of S from SH-radicals of two molecules of Reduced form of Glutathione or between atom of O of a carboxyl group and atom of S of SHradical of molecule of Glutathione as in result of interaction of zinc with diabetognic derivatives of 8-oxyquinolin.