title: Ablation of capsaicin-sensitive afferent nerves affects insulin response during an intravenous glucose tolerance test.
abstract: We investigated the role of sensory nerves in glucose tolerance in conscious Wistar rats neonatally treated with neurotoxin capsaicin or vehicle. Intravenous glucose tolerance tests (IVGTT, 150, 300 and 450 mg in 30 min) were performed to measure glucose tolerance, and glucose, insulin and glucagon levels were measured. Higher glucose concentration resulted in a greater insulin response in both capsaicin- and vehicle-treated rats. However, glucose-stimulated insulin secretion was attenuated in capsaicin-treated animals, even though glucose levels did not differ. Glucagon levels did not differ between both groups. These results show that capsaicin-sensitive nerves are involved in glucose-stimulated insulin secretion, but are not directly involved in the regulation of blood glucose levels. Moreover, they suggest that capsaicin-sensitive nerves could be involved in the regulation of insulin sensitivity. We hypothesize that sensory afferents could play a role in the aetiology of pathologies where glucohomeostatic mechanisms are disturbed, as is in type 2 diabetes mellitus.
authors.affiliation: Department of Animal Physiology, Biology, Biological Center, University of Groningen, P.O. Box 14, 9750 AA Haren, Groningen, The Netherlands. E.H.E.M.van.de.Wall@rug.nl
authors.forename: Esther H E M
authors.initials: EH
authors.lastname: van de Wall
authors.forename: Dorte X
authors.initials: DX
authors.lastname: Gram
authors.forename: Jan H
authors.initials: JH
authors.lastname: Strubbe
authors.forename: Anton J W
authors.initials: AJ
authors.lastname: Scheurink
authors.forename: Jaap M
authors.initials: JM
authors.lastname: Koolhaas
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005934:Glucagon / Q000097:blood; D005951:Glucose Tolerance Test; D007328:Insulin / Q000097:blood / Q000378:metabolism*; D008297:Male; D009475:Neurons, Afferent / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D001786:Blood Glucose; D007328:Insulin; D005934:Glucagon; D002211:Capsaicin