Serum gastrin response to feeding in achlorhydric patients

We have measured the serum gastrin response to feeding in 3 groups of achlorhydric patients, and have compared the results with those of 12 normal controls. An increased postprandial serum gastrin response was found in 6 of 8 patients with hypergastrinemia and pernicious anemia, in all 10 patients with hypergastrinemia and normal absorption of vitamin B12, and in 2 of 7 achlorhydric patients with normal fasting serum gastrin levels. A reduced serum gastrin response to feeding was found in 2 patients with pernicious anemia and very high basal serum gastrin levels of 3,010 and 3,800 pg/ml, and in one achlorhydric patient with normogastrinemia. The remaining 4 patients with achlorhydria and normogastrinemia had normal postprandial serum gastrin responses. It is concluded that the serum gastrin response to feeding in patients with achlorhydria is heterogeneous.