Neonatal capsaicin-treatment in mice: effects on pancreatic peptidergic nerves and 2-deoxy-D-glucose-induced insulin and glucagon secretion.
It is not known whether sensory nerves are involved in the insulin, glucagon or glucose responses to autonomic nerve activation induced by 2-deoxy-D-glucose (2-DG). We therefore treated mice neonatally with capsaicin which permanently destroys sensory afferent nerve fibers. Immunohistochemistry of the pancreas at 13-14 weeks of age revealed a substantial reduction of calcitonin gene-related peptide (CGRP)-immunoreactive nerves and a partial reduction of substance P-immunoreactive nerves. In contrast, no effect was observed on galanin-immunoreactive nerves. At age 10-12 weeks, the mice were injected intravenously with 2-DG (500 mg/kg). In controls, 2-DG stimulated insulin and glucagon secretion and induced hyperglycemia (P less than 0.01). Capsaicin treatment partially reduced the glucose and glucagon responses to 2-DG (P less than 0.01). In contrast, the insulin response to 2-DG was not affected by capsaicin. It is concluded that the mouse pancreas contains capsaicin-sensitive sensory CGRP- and substance P-immunoreactive nerve fibers, whereas the galanin-immunoreactive nerve fibers are not sensitive to capsaicin. Furthermore, capsaicin-sensitive sensory nerve fibers are partially involved in 2-DG-induced glucagon secretion and hyperglycemia, whereas sensory nerves are not involved in 2-DG-induced insulin secretion.
Karlsson
S
S
Department of Pharmacology, Lund University, Sweden.
Sundler
F
F
Ahrén
B
B
D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D001786:Blood Glucose / Q000378:metabolism; D015740:Calcitonin Gene-Related Peptide / Q000276:immunology / Q000378:metabolism; D002211:Capsaicin / Q000494:pharmacology*; D003847:Deoxyglucose / Q000494:pharmacology*; D005260:Female; D019004:Galanin; D005934:Glucagon / Q000378:metabolism*; D007150:Immunohistochemistry; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D051379:Mice; D009479:Neuropeptides / Q000502:physiology*; D010179:Pancreas / Q000187:drug effects / Q000294:innervation / Q000378:metabolism*; D010455:Peptides / Q000276:immunology / Q000378:metabolism; D013373:Substance P / Q000276:immunology / Q000378:metabolism
D001786:Blood Glucose; D007328:Insulin; D009479:Neuropeptides; D010455:Peptides; D013373:Substance P; D019004:Galanin; D005934:Glucagon; D003847:Deoxyglucose; D015740:Calcitonin Gene-Related Peptide; D002211:Capsaicin