Abstract
Carbohydrate intolerance has been observed in the subjects with pheochromocytoma and the decreased glucose tolerance is completely or partially reversed by removal of the tumor. Inhibition of insulin secretion by catecholamine has been reported by Porte and his co-workers. The evidence has been given by a few authors in human subjects with pheochromocytoma. Investigation has been made on insulin response to glucose and tolbutamide before and after the removal of the tumor in a patient with pheochromocytoma.
The patient, 36 years old, engineer, was admitted to hospital for hypertension of 14 years' duration and diabetes mellitus. Blood pressure ranged from 206 to 150mmHg systolic and from 110 to 90 diastolic. Fasting blood sugar was 229mg/100ml, which gradually decreased by dietary therapy. After renal biopsy, he complained of abdominal pain at the right upper quadrant and his blood pressure fell to 76 mmHg. Immediately, he underwent laparotomy. A large mass, 155 g, was removed from the right kidney. Diabetes mellitus which had been observed at the preoperative period disappeared after the removal of the tumor. Glucose tolerance curve obtained before the operation showed a severe type of diabetes mellitus, but it was completely reversed after the removal of the tumor. Insulin response to glucose, which had been depressed before the operation, was improved after the removal of the tumor. A decreased insulin response to tolbutamide at the preoperative period was corrected after the operation.
These data support the hypothesis that a decreased glucose tolerance observed in the patients with pheochromocytoma may be mediated by inhibition of insulin secretion due to chronically secreting catecholamine.
