title: [Role of transmembrane ion currents in the mechanism of action of beta-adrenoblockers].
abstract: The effects of propranolol, oxprenolol, pindolol, labetalol, and atenolol on the isoproterenol-stimulated slow calcium current as well as on spontaneous slow calcium and fast sodium currents were studied in frog trabeculae by the double sucrose bridge technique. Administration of beta-adrenoblockers in low doses (10(-7)-10(-6)M) antagonized the stimulatory effect of isoproterenol on the slow calcium current (pindolol greater than oxprenolol greater than or equal to propranolol = labetalol greater than atenolol). When administered in high doses (2 X 10(-6)-10(-4)M) the beta-adrenoblockers reduced the slow calcium current. Meanwhile, some of them (propranolol, oxprenolol, labetalol) suppressed the fast sodium current.
mesh_terms: D000319:Adrenergic beta-Antagonists / Q000494:pharmacology*; D000818:Animals; D001262:Atenolol / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D007473:Ion Channels / Q000502:physiology*; D007741:Labetalol / Q000494:pharmacology; D010096:Oxprenolol / Q000494:pharmacology; D010869:Pindolol / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011895:Rana ridibunda
chemical_list: D000319:Adrenergic beta-Antagonists; D007473:Ion Channels; D001262:Atenolol; D010096:Oxprenolol; D011433:Propranolol; D010869:Pindolol; D007741:Labetalol
vernacular_title: Issledovanie roli transmembrannykh ionnykh tokov v mekhanizme deĭstviia beta-adrenoblokatorov.