The effect of insulin-induced hypoglycaemia on serum group I pepsinogens, serum gastrin, and plasma secretin and on gastric H+ and pepsin outputs.

The effect of insulin-induced hypoglycaemia on serum group I pepsinogens (PG I), serum gastrin, and plasma secretin, and on gastric H+ and pepsin secretion was studied on 2 consecutive days in six healthy male students. The hypoglycaemia elicited a significant rise in serum PG I on both days. Furthermore, an increase in basal serum PG I was noted from the first to the second day, with a further increase the third day. Serum gastrin, which was not significantly affected, nevertheless tended to peak immediately after the nadir of the blood glucose value. Plasma secretin, on the other hand, fell significantly during gastric suction before the injection of insulin on the second day and non-significantly on the first day. A further declining tendency in plasma secretin was observed after insulin injection. Gastric H+ and pepsin outputs increased significantly on both days. There was no significant difference in gastric H+ response on the 2 days, whereas peak gastric pepsin output was significantly reduced on the second day. It is concluded that the rise in serum PG I probably reflects an increased synthesis of pepsinogens and that the fall in peak gastric pepsin output on the second day may reflect reduced storage of pepsinogens in the chief cells.