Abstract
It was found that thiamine 8-(methyl 6-acetyldihydrothioctate) disulfide (TATD) reducing activity in erythrocyte hemolysate was heat stable and above 90% of it was inhibited by N-ethylmaleimide and p-chloromercuribenzoate. Experimental results from dialysis treatment of the hemolysate showed that reduced glutathione (GSH), out of sulfhydryl compounds in erythrocytes, held a main part of TATD reducing activity. When erythrocyte was incubated with TATD, consumption of GSH in erythrocytes has been noted according to the increase of added TATD concentration. This change of GSH level was also observed by using of thiamine propyldisulfide in place of TATD. The presence of glucose or inosine suppressed apparently the consumption of GSH. Restoration of GSH level was observed by incubation of erythrocytes in Krebs-Ringer phosphate buffer (pH7.4) after the repeated washings of the erythrocytes separated from reaction mixture with TATD and the restoration was accelerated by the addition of glucose or inosine in incubation medium. No remarkable differences of total glutathione (reduced plus oxized) were found among the intact-, TATD treated- and restored-erythrocytes. This suggests that the consumption of GSH by the incubation of erythrocytes withTATD reflects the change of GSH to its oxidized form and the recovery of reduced form is proceeded by glutathione reductase system in erythrocytes which is probably stimulated through the enhanced supplying of NADPH by glucose or inosine.
