In this study we evaluated the short-term hormonal effects of segmental and whole pancreatic allotransplantation on the glucose intolerance produced by hemipancreatectomy in the primate. In hemipancreatectomized animals without grafts the K-values were reduced to 0.6 +/- 0.05, plasma insulin increased from 27.5 +/- 2.5 to 63.5 +/- 6.3 microU/ml, and glucagon levels declined from 252 +/- 29.9 to 216.5 +/- 33.0 pg/ml. Hemipancreatectomized segmental allograft recipients rendered K-values of 0.79 +/- 0.05, plasma insulin increased from 19.98 +/- 3.43 to 66.0 +/- 17.03 microU/ml, and glucagon release declined from 395.6 +/- 63.0 to 226.2 +/- 37.6 pg/ml during IVGTT postoperatively. Hemipancreatectomized, pancreaticoduodenal allograft recipients rendered K-values of 0.82 +/- 0.1, results not significantly different from hemipancreatectomized or segmental allograft recipients. Plasma insulin increased from 29.5 +/- 4.0 to 186.0 +/- 25.0 microU/ml, and glucagon release declined from 1,087.0 +/- 31.6 to 656.0 +/- 12.7 pg/ml. In summary, segmental pancreatic allotransplantation could not, in the short-term, restore the reduced K-values and hypoinsulinaemia in hemipancreatectomized primates to that of normal, unstressed controls. Although K-values of hemipancreatectomized recipients were not significantly improved, whole pancreas transplantation resulted in improved insulin release and hyperglucagonaemia during IVGTT when compared to segmental allograft recipients. The unexpected findings of hypoinsulinaemia and hyperglucagonaemia in both transplant groups may only reflect a function of the stressed state of the animals in the immediate postoperative phase.