Regulation of Glutathione Homeostasis in Adolescents With Type 1 Diabetes - Study A

Adolescents with uncomplicated T1D will receive two, 5-hour infusions of deuterium-labeled cysteine on 2 separate days, a few weeks apart, while blood glucose will be maintained, using intravenous insulin infusion: * in the hyper-glycemic range (200-250 mg/dL) on one study day, and * near normoglycemia (80-140 mg/dL) on the other study day. The order of the study days will be randomized. We will determine whether the level of blood glucose at the time of study affects blood glutathione concentration, and, if so, whether this is associated with changes in the fractional rate of glutathione synthesis, as determined from the incorporation of labeled cysteine into blood glutathione over the course of the 5-hr infusion of labeled cysteine.