title: Effects of imidazolines and derivatives on insulin secretion and vascular resistance in perfused rat pancreas.
abstract: The effects of imidazolines and derivatives were studied on insulin secretion and vascular resistance in the isolated perfused rat pancreas. On insulin secretion, two imidazoline alpha 2-adrenoceptor antagonists, efaroxan (1-100 microM) and RX821002 (10 microM), had a stimulating response; however, idazoxan, like the non-imidazoline alpha 2-adrenoceptor antagonist yohimbine, was ineffective at 10 microM. The oxazoline rilmenidine with alpha 2-adrenergic activity at 10 microM), an imidazoline devoid of alpha 2-adrenergic activity, also had an insulin-releasing effect. On pancreatic vessels, all imidazolines tested (efaroxan, RX821002, antazoline and idazoxan), in contrast to yohimbine, induced vasoconstriction. Rilmenidine did not have a vasoconstrictor effect after blockade of alpha 2-adrenoceptors. Furthermore, the efaroxan-induced insulin release or vasoconstriction was not affected by the blockade of alpha 2- and alpha 1-adrenoceptors. This study shows that imidazolines and derivatives are able to stimulate insulin release and induce vasoconstriction in the rat pancreas. These effects cannot be ascribed to an interaction with alpha-adrenoceptors but may involve different types of imidazoline sites.
authors.affiliation: Faculté de Médecine, Institut de Biologie, Montpellier, France.
authors.forename: D
authors.initials: D
authors.lastname: Berdeu
authors.forename: R
authors.initials: R
authors.lastname: Gross
authors.forename: G
authors.initials: G
authors.lastname: Ribes
authors.forename: M M
authors.initials: MM
authors.lastname: Loubatières-Mariani
authors.forename: G
authors.initials: G
authors.lastname: Bertrand
mesh_terms: D058668:Adrenergic alpha-1 Receptor Antagonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D000865:Antazoline / Q000494:pharmacology; D001572:Benzofurans / Q000494:pharmacology; D007093:Imidazoles / Q000494:pharmacology*; D066298:In Vitro Techniques; D007328:Insulin / Q000378:metabolism*; D000078790:Insulin Secretion; D008297:Male; D010179:Pancreas / Q000098:blood supply / Q000187:drug effects / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects; D018341:Receptors, Adrenergic, alpha-2 / Q000187:drug effects; D012039:Regional Blood Flow / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects
chemical_list: D058668:Adrenergic alpha-1 Receptor Antagonists; D058669:Adrenergic alpha-2 Receptor Antagonists; D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D001572:Benzofurans; D007093:Imidazoles; D007328:Insulin; D018340:Receptors, Adrenergic, alpha-1; D018341:Receptors, Adrenergic, alpha-2; D000865:Antazoline; C062597:efaroxan