Service, F J

The optimal route for insulin administration by insulin infusion devices has not been established. To assess the differences between the peripheral venous and portal venous routes of insulin administration on postprandial metabolic responses, six alloxan-diabetic dogs were studied on four occasions. On the first, the insulin infusion rates given by the Biostator for disposal of a mixed meal were recorded electronically. On two subsequent occasions, these insulin infusion profiles were administered by a peripheral vein. On an additional occasion, the identical insulin infusion profile was given via the portal vein. No differences were observed in basal or peak plasma glucose, insulin, glucagon, branched chain amino acids, and lactate concentrations between portal and peripheral venous insulin administration. Furthermore, no differences in isotopically ([2-3H]glucose) determined rates of systemic glucose appearance and disappearance were observed between the two routes. Although preprandial plasma alanine concentrations were greater when insulin was infused via the portal vein, the postprandial increments did not differ from those observed during infusion of insulin by a peripheral vein. These studies suggest that under the current experimental conditions, there appears to be no difference in the disposition of a mixed meal, measured as net whole body glucose appearance and disappearance rates, when insulin is administered in an open-loop fashion via either a peripheral or the portal vein.

Abstract Background The authors have reported a newly recognized hypoglyacemic disorder, non-insulinoma pancreatogenous hypoglycaemia syndrome (NIPHS), which is characterized by postprandial hyperinsulinaemic hypoglycaemia, negative 72-h fast, negative transabdominal and intraoperative ultrasonography, spiral computed tomography and coeliac axis angiography, positive selective arterial calcium stimulation test (SACST), absence of insulinoma but presence of islet hypertrophy and nesidioblastosis, and relief of symptoms from gradient-guided partial pancreatectomy. Experience with the next five patients with this disorder (6–10; 1998–1999) compared with the original five (1–5; 1996–1998) is reported. Results Wide age range, male predominance, postprandial occurrence of symptoms, negative radiological localization, nesidioblastosis/islet hypertrophy, but no insulinoma characterized all ten cases. Response to SACST indicated widespread islet hyperfunction in patients 1 and 5; limitation to distribution of the SPA and GDA in patients 3, 4, 6 and 8, to distribution of the SPA in patients 2, 7 and 9, and to distribution of the SMA in patient 10. Except for patient 5, pancreatic resection to the left of the SMV was performed when only the SPA was positive on the SACST. Patients 5 and 8 have had recurrence of symptoms; they resolved within 3 months for patient 5. Conclusion NIPHS can usually be treated successfully with gradient-guided partial pancreatectomy.