Sympathetic Nerve Stimulation Versus Pancreatic Norepinephrine Infusion in the Dog: 1) Effects on Basal Release of Insulin and Glucagon

TLDR: Whether pancreatic norepinephrine infusions could reproduce the inhibition of insulin secretion and the stimulation of glucagon secretion observed during sympathetic nerve stimulation in halothane-anesthetized dogs was investigated.

Abstract: We investigated whether pancreatic norepinephrine (NE) infusions could reproduce the inhibition of insulin secretion and the stimulation of glucagon secretion observed during sympathetic nerve stimulation in halothane-anesthetized dogs. Three minutes of stimulating the sympathetic nerves (8 Hz, 1 msec, 10 mA, n = 6) surrounding the pancreatic artery decreased both the blood flow in the superior pancreatic vein (SPV) (Δ = -1.7 ± 0.6 ml/min, P < 0.05) and the basal pancreatic output of immunoreactive insulin (IRI) (Δ = –79 ± 5%, P < 0.001). SPV levels of NE increased by 683 ± 177 pg/ml (P < 0.02). Infusion of NE into the superior pancreatic artery at the low dose of 12 ng/min (n = 6) reproduced this increase of SPV levels of NE (Δ= +740 ± 130 pg/ml; P < 0.01) and caused a small reduction of SPV blood flow (Δ= -1.0 ± 0.4 ml/min, P < 0.05), but did not change pancreatic IRI (Δ= -26 ± 16%, NS). The medium dose of NE (120 ng/min, n = 6) reproduced the nerve stimulation-induced decrease of SPV blood flow (Δ= -1....