The capacity of autotransplanted (
ATP) distal pancreas segments with systemic venous and peritoneal exocrine drainage to support physiologic control of plasma
glucose levels was tested, and compared with the functions of "simulated autotransplants" (
SATP) prepared with similar dissection and peritoneal exocrine drainage, but with hepatic portal venous drainage, in dogs. In
ATP in the postabsorptive state, plasma levels of
glucose, immunoreactive
insulin (IRI) and immunoreactive
glucagon (IRG1) were normal. Autotransplants resulted in
impaired glucose tolerance after meals with impaired early
insulin responses, and the normal brisk rise of IRG1 in the plasma was delayed and reduced through the first 30 min of feeding. In
ATP, also, the response to
bombesin was abnormal; the normal stimulation of release of both IRI and IRG1 was delayed in both cases. In studies of responses to oral and intravenous
glucose in
ATP and
SATP dogs, similar mild degrees of
glucose intolerance were found with both routes of administration; however, whereas in
ATP dogs increases of IRI were highly exaggerated with both routes of administration of
glucose, in
SATP dogs plasma IRI rose from subnormal levels in the postabsorptive state through subnormal increments with both routes of administration. Further studies are necessary to determine the relative importance of
denervation and reduction of the mass of the pancreas in these effects, and to assess the significance of the differences in blood
insulin levels in the two preparations.