D. Grassetti, J. B. Murray
Dec 1, 1967
Citations
0
Influential Citations
15
Citations
Journal
Biochemical pharmacology
Abstract
Abstract (1) 2,2'-Dithiodipyridine (2-PDS) reacts with thiols with formation of a disulfide and 2-thiopyridone. The latter compound can be determined by its u.v. absorption. The inhibition of respiration of Ehrlich ascites cells by 2-PDS is probably due in large extent to the oxidation of cell thiols to disulfides. When enzymatic reactions do not occur, as in heat-denatured ascites cells and mouse tissues, a smaller amount of 2-PDS is consumed than with live tissues. (2) The oxidation of glutathione by 2-PDS (GSH → GSSG) can be coupled to the reduction of GSSG by NADPH (catalyzed by glutathione reductase). This leads to continuous reoxidation of the GSH formed, and the overall process is the oxidation of NADPH by 2-PDS (a reaction that does not occur spontaneously). (3) 2-PDS is a substrate for glutathione reductase, oxidizing NADPH at about 1/200 the rate of glutathione. This reaction can be coupled to the oxidation of glucose 6-phos-phate by NADP + (catalyzed by glucose 6-phosphate dehydrogenase). (4) The reactions described in (2) and (3) above could take place in the cell, and thus account for the “extra” amount of 2-PDS used by metabolically active cells.