Some metabolic responses to intravenous tolbutamide in patients with cystic fibrosis of the pancreas

Following stimulation with intravenous tolbutamide, the plasma glucose, lactate and pyruvate of children with cystic fibrosis and of controls were analyzed by standard technics. Both groups included children with diabetes mellitus. The experiment had been prompted by the observation that children who have both cystic fibrosis and diabetes excrete less ketone in the urine than expected. Glucose, lactate and pyruvate were decreased in normal children, whereas only glucose and pyruvate were decreased in children with cystic fibrosis alone. The children with cystic fibrosis and diabetes responded the same as those with diabetes alone. The antiketogenic tendency cannot be explained on the basis of an abnormal accumulation of lactate or pyruvate. Further metabolic explorations in cystic fibrosis might reveal new manifestations of the underlying process.