title: The dual effect of isoproterenol on insulin release is suppressed in pancreatic islets from hypothalamic obese rats.
abstract: Hyperinsulinemia in obesity has been attributed to insulin oversecretion by pancreatic beta-cells. Beta-cells are equipped with cholinergic and adrenergic receptors; whereas overall acetylcholine action is to potentiate, catecholamines' effect is to inhibit glucose-induced insulin release (GIIR) via alpha2-adrenoceptor. However, it has been shown that beta-adrenergic agonists potentiate glucose response. GIIR was studied in pancreatic islets from hyperinsulinemic adult obese rats, obtained by L-glutamate monosodium (MSG) neonatal treatment. Islets from MSG-rats were more glucose responsive than control ones. Isoproterenol, a beta-adrenergic agonist, inhibited the GIIR in islets from MSG-obese rats. Results indicate that MSG treatment causes alteration on function of beta-cell adrenoceptors.
authors.affiliation: Laboratory of Secretion Cell Biology, Department of Cell Biology and Genetics, State University of Maringá, Maringá, PR, Brazil.
authors.forename: Anderson Carlos
authors.initials: AC
authors.lastname: Marçal
authors.forename: Sabrina
authors.initials: S
authors.lastname: Grassiolli
authors.forename: Diego Neves
authors.initials: DN
authors.lastname: da Rocha
authors.forename: Marcelo Aguilar
authors.initials: MA
authors.lastname: Puzzi
authors.forename: Clarice
authors.initials: C
authors.lastname: Gravena
authors.forename: Dionízia Xavier
authors.initials: DX
authors.lastname: Scomparin
authors.forename: Paulo Cezar
authors.initials: PC
authors.lastname: de Freitas Mathias
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001786:Blood Glucose / Q000032:analysis; D006946:Hyperinsulinism / Q000139:chemically induced; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D007515:Islets of Langerhans / Q000187:drug effects / Q000378:metabolism*; D007545:Isoproterenol / Q000494:pharmacology*; D008297:Male; D009765:Obesity / Q000139:chemically induced / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D012970:Sodium Glutamate / Q000494:pharmacology
chemical_list: D001786:Blood Glucose; D007328:Insulin; D007545:Isoproterenol; D012970:Sodium Glutamate