Endocrine Abstracts

It was proved that zinc complexes of both metformin and phenformin could act as protease inhibitors with potency at therapeutic concentrations. Biguanide-metal complexes turned out to be more potent cysteine protease inhibitors than either the biguanide or zinc ions alone, i.e. showed synergistic effect. It can be assumed that changes in state of metabolism of zinc induced by ageing, genetic predispositions, accompanying diseases, and some other drugs administered to diabetic patients affect the therapeutic efficiency of biguanides. Because with age serum concentration of zinc and level of its transmembrane transport are getting lower, a decrease of effectiveness of biguanides can be expected. The same effect is observed in a course of various acute and chronic diseases. In turn, some medications that induce an increase of serum zinc concentration and activate its transmembrane migration are probable to enhance a hypoglycemic efficiency of biguanides. The effects presented herein can be also discussed in relation to Zn(2+)-interactive inhibition of insulin degradation in hormone target tissues.