実験糖尿病におよぼす含硫化合物の影響(第8報)チオール・ジスルフィド水素転移酵素, グルタチオン還元酵素, グルコース-6-リン酸脱水素酵素に対するチオール・ジスルフィド化合物の影響

抄録

Effect of thiol and disulfide compounds on thiol-disulfide transhydrogenase (TDTH), glutathione reductase (GR), and glucose-6-phosphate dehydrogenase (G6PD) were studied in normal and alloxan-diabetic rats. 1. In both in vitro and in vivo experiments, GR activity in the pancreas, liver, and kidney of normal and alloxan diabetic (AD) rats was inhibited by glutathione (GSH), 2-mercaptopropionylglycine (MPG), and cysteine, while there was no significant difference in the GR activity between rats receiving the oxidized form of these three compounds and the control. 2. GSH-oxidized MPG-TH activity and GSH-cystine-TH activity in vitro and in vivo were examined and neither MPG nor cysteine was found to produce a significant difference in the TDTH activity. 3. G6PD activity in vivo was increased in the early period after GSH and MPG administration. The oxidized form of these compounds decreased G6PD activity. The results of these experiments showed that thiol compounds had effect on GR activity and indirectly increased glucokinase (GK) activity. Oxidized GSH had no effect on these three enzymes for GK assay, but acted directly GK enzyme and decreased GK activity. It is of great interest that thiol compounds have a stronger effect on the enzymes in AD rats than in normal rats.