Paradoxical elevations of plasma glucagon levels in patients after pancreatectomy or gastrectomy.

In twenty-five patients undergoing total pancreatectomy (TP), twenty distal gastrectomy (DG) and twenty healthy subjects, effects of oral glucose loading on the plasma glucagon (IRG) levels were determined. Plasma IRG levels were elevated after glucose loading in the TP and DG patients, but not in the healthy subjects. To clarify events related to the elevations in IRG, the plasma IRG components were analyzed by gel filtration in 6 of the TP patients, 5 of the DG patients and 4 of the controls. In the TP group, IRG3500 was not detectable either in the basal state or after glucose loading, while IRG9000 was markedly increased after glucose (p less than 0.002). In the DG group, IRG3500 was significantly suppressed after glucose (p less than 0.05), but IRG9000 was clearly increased (p less than 0.005). In the controls, IRG3500 was suppressed after glucose (p less than 0.05), however, IRG9000 was not detected throughout the examination. Thus, in patients with TP or DG, the essential cause of the high responses of plasma glucagon after oral glucose loading was the increase in IRG9000. Because the food passage route is much the same in TP and DG patients, the IRG9000 elevations are probably related to secretion in the digestive tract.