Enhancement of renal and hepatic glutathione metabolism by dimethylthiourea

Dimethylthiourea (DMTU), a free radical scavenger, was administered to rats to study its effect on renal and hepatic glutathione metabolism, since it is a potential sulfhydryl donor. Six hours following DMTU, renal GSH content was significantly ( P < 0.05) increased (10%), and was increased further after 24 h (28%) ( P < 0.001). Hepatic GSH content was also significantly ( P < 0.001) elevated at 6 and 24 h (5 and 33%, respectively). Seven days of daily DMTU therapy significantly ( P < 0.001) increased renal and hepatic GSH content by 36 and 54%, respectively, which was associated with a significant ( P < 0.001) increase in the renal activities of glutathione peroxidase (GP) by 38%, glutathione transferase (GT) by 92%, and glutathione reductase (GR) by 19% ( P < 0.05). Significantly increased activities of hepatic GP by 84% ( P < 0.01) and GT by 101% ( P < 0.001) also occurred in DMTU-treated rats after 7 days of continuous therapy. From these data, we conclude that DMTU stimulates renal and hepatic GSH metabolism, which may be important in mediating DMTU's protective effect against free radical-induced tissue injury.