The effect of a test meal on serum group I pepsinogens (PG I) and serum gastrin in persons with normal gastric H+ secretion and in persons with achlorhydria.

Thirteen persons with normal pentagastrin-stimulated gastric H+ secretion and 17 with achlorhydria were studied with a liquid test meal after an overnight fast. Blood was drawn before and every 30 min for 180 min after start of the meal. Serum gastrin, serum PG I, and serum vitamin B12 were determined by radioassay methods. Serum PG I was significantly lower in the achlorhydric subjects than in the normal secretors. The meal induced a slight and late rise in serum PG I in the control group. In contrast, the meal caused a slight fall in the achlorhydric persons. Basal serum gastrin was significantly higher in the achlorhydric group, in whom the meal also caused a significant fall in serum gastrin, which contrasts sharply with the rise in the control group. Although serum gastrin fell significantly in the achlorhydric group, a meal-induced rise in serum gastrin was observed in some of the achlorhydric subjects with basal serum gastrin below 100 pmol/l. Serum vitamin B12 was reduced in 8 of the 17 persons with achlorhydria, and in these 8 subjects serum PG I was significantly lower than in those with achlorhydria and normal serum vitamin B12.