The metabolic clearance of endogenous immunoreactive glucagon and exogenous glucagon in pancreatectomized and sham-operated pigs.

Hyperglucagonemia follows feeding in the pancreatectomized pig as it does in the pancreatectomized dog and man, but the cause of the rise in glucagon concentration is unknown. We report here the metabolic clearance and t½ of exogenous porcine glucagon infused into pigs and of endogenous immunoreactive glucagon (IRG) depressed by infusion of somatostatin. Somatostatin suppressed IRG levels to 70% of basal levels in pancreatectomized (P) pigs within 20 min of commencement of infusion and to 30% thereof in shamoperated (S) pigs within 50–60 min of commencement of infusion. In the S animals there was a breakthrough rebound within 6-8 h to levels approximately 175% of basal despite continued somatostatin infusion, while in the P animals a breakthrough to levels just above basal took place at 2 h in only two of seven animals. In the remaining five animals there was no rebound phenomenon. The half-life times determined from the slopes of disappearance were 42 ± 13 min in S animals and 55 ± 10 in P animals. In co...