Donors undergoing hemi-
pancreatectomy to provide a pancreas segment for
transplantation into a relative with
type 1 diabetes acquire diminished
insulin and
glucagon responses to intravenous agonists. Some donors develop diabetes and require treatment for
hyperglycemia. They become at risk for
hypoglycemia when treatment includes sulfonylureas and
insulin. However, no studies assessing the impact of hemi-
pancreatectomy in humans on islet alpha-cell responses to
hypoglycemia have been reported. Consequently, we performed stepped
hypoglycemic clamps in 7 donors of varying
glycemic control and compared their responses to 16 control subjects. Donors and control subjects reached similar nadirs of glycemia (45 +/- 3 and 41 +/- 1 mg/dl, respectively) during the clamp. The donors had significantly higher mean basal
glucagon levels than control subjects (203 +/- 27 vs. 135 +/- 15 pg/ml; P < 0.03) but did not have significant differences in
glucagon responses during the clamp. The donors also had significantly higher mean peak
epinephrine responses during the clamp (1,231 +/- 134 vs. 730 +/- 68 pg/ml; P < 0.002), but there were no statistically significant differences in
norepinephrine or symptom responses. The
glucose thresholds at which hormonal and symptom responses began were not different. We conclude that although
glucagon response to
arginine and
insulin response to
glucose and
arginine are diminished after hemi-
pancreatectomy, no deficiency in
glucagon responses were detected during
hypoglycemia.