After pancreatectomy and heterotopic pancreatic allotransplantation in dogs, there was a pattern of endocrine activity similar to that found following a combination of pancreatic denervation and total transposition of the pancreatic venous effluent from the portal to the systemic venous circulation. Denervation of the pancreas alone or total venous transposition alone did not mirror these results. The mechanism of the effect of these two factors is discussed.