title: Involvement of the vagus nerves in the regulation of basal hepatic glucose production in conscious dogs.
abstract: We determined if blocking transmission in the fibers of the vagus nerves would affect basal hepatic glucose metabolism in the 18-h-fasted conscious dog. A pancreatic clamp (somatostatin, basal portal insulin, and glucagon) was employed. A 40-min control period was followed by a 90-min test period. In one group, stainless steel cooling coils (Sham, n = 5) were perfused with a 37 degrees C solution, while in the other (Cool, n = 6), the coils were perfused with -20 degrees C solution. Vagal blockade was verified by heart rate change (80 +/- 9 to 84 +/- 14 beats/min in Sham; 98 +/- 12 to 193 +/- 22 beats/min in Cool). The arterial glucose level was kept euglycemic by glucose infusion. No change in tracer-determined glucose production occurred in Sham, whereas in Cool it dropped significantly (2.4 +/- 0.4 to 1.9 +/- 0.4 mg. kg(-1). min(-1)). Net hepatic glucose output did not change in Sham but decreased from 1.9 +/- 0.3 to 1.3 +/- 0.3 mg. kg(-1). min(-1) in the Cool group. Hepatic gluconeogenesis did not change in either group. These data suggest that vagal blockade acutely modulates hepatic glucose production by inhibiting glycogenolysis.
authors.affiliation: Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0615, USA.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Cardin
authors.forename: Konstantin
authors.initials: K
authors.lastname: Walmsley
authors.forename: Doss W
authors.initials: DW
authors.lastname: Neal
authors.forename: Phillip E
authors.initials: PE
authors.lastname: Williams
authors.forename: Alan D
authors.initials: AD
authors.lastname: Cherrington
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000096:biosynthesis*; D001831:Body Temperature / Q000502:physiology; D003080:Cold Temperature; D003243:Consciousness; D004285:Dogs; D005215:Fasting / Q000502:physiology; D005260:Female; D005934:Glucagon / Q000097:blood; D005943:Gluconeogenesis / Q000502:physiology; D006339:Heart Rate; D007328:Insulin / Q000097:blood; D008066:Lipolysis / Q000502:physiology; D008099:Liver / Q000294:innervation* / Q000378:metabolism*; D008297:Male; D010276:Parasympatholytics / Q000494:pharmacology; D014630:Vagus Nerve / Q000502:physiology*
chemical_list: D001786:Blood Glucose; D007328:Insulin; D010276:Parasympatholytics; D005934:Glucagon