Increased gastrin secretion in patients with pheochromocytoma.

The relationship between serum catecholamines and serum gastrin in the basal state and in response to a liquid test meal was investigated in 6 patients with histologically proven pheochromocytoma before and after surgical removal of the tumor. Serum catecholamines were measured by a high performance liquid-chromatography technique, and serum gastrin was determined by radioimmunoassay. In patients with normal serum adrenaline, no increase in serum gastrin level in the basal state or after ingesting a test meal was found. In contrast, in those with abnormally high serum adrenaline, the serum gastrin levels in the basal state and in response to a test meal were significantly higher than in patients with a normal serum adrenaline level and in normal subjects. Surgical removal of the tumor resulted in a significant decrease in both the serum adrenaline concentration and serum gastrin secretion in the basal state and after meal stimulation. These results indicate that adrenaline stimulates serum gastrin secretion not only in the basal state, but also in response to a test meal.