and I-elerans .4 d nr inist ru t ici n Hospital, Dallas.To ascertain whether arylsulfonylurea compounds influence blood glutathione concentrations, determinations of reduced glutathione were made following oral administration of tolbutamide (Orinase) + or carbutamide (BZ-5 5 ) t to patients with normal carbohydrate metabolism and patients with mild diabetes niellitus. Glutathione values were much lower in the diabetic patients both before and after administration of the sulfonylureas. However. no change in glutathione levels was observed in either group during the acute hypoglycemic response to these compounds. nor in diabetic patients who received therapeutic doses of tolbutamide for several days. nlaterial and methods. The patients were all men. Each of 9 control patients had a normal oral glucose tolerance test. Twelve of the 15 diabetic patients were eating a t least 200 g of carbohydrate daily. while the others received 150 g daily. Insulin had never been given to 12 of the diabetics. and had been discontinued in the others a t least one week before the test. The ages of control patients ranged from 24 to 62 years, with a mean of 37 years. The diabetic patients were older, from 46 to 68 years of age with a mean of 59 years, since most of them were selected for probable susceptibility to sul fonylureas. Liver function tests were normal in all 24 individuals. Following an overnight fast 3 g of tolbutamide were given orally to all control patients and to 1 1 of those with diabetes. The other 4 diabetics received 3 g of carbutamide orally. Oxalated specimens of venous blood were obtained before administration of sulfonylurea and a t hourly intervals for 5 hours. Duplicate determinations on whole blood were done for glucose by the Somogyi-*This study was supported in part by research t Tolbutamide was kindly supplied by Upjohn Co., grant from U. S. Public Health Service. and carbutamide by Eli Lilly and Co.