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

Abstract

In twenty-five patients undergoing total pancreatectomy (TP), twenty distal gastrectomy (DG) and twenty healthy subjects, effects of oral glucose loading on the plasma gluccagon (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<0.002). In the DG group, IRG³⁵⁰⁰ was significantly suppressed after glucose (p<0.05), but IRG⁹⁰⁰⁰ was clearly increased (p<0.005). In the controls, IRG³⁵⁰⁰ was suppressed after glucose (p<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.