title: Calcium mechanism of norepinephrine activation of ionic pump in somatic cells of lumbricus terrestris earthworm muscle wall.
abstract: Blockade of norepinephrine-induced hyperpolarization in earthworm muscle cells was observed in a calcium-free medium, after substitution of Ca(2+)with Mn(2+), and in the presence of verapamil or chlorpromazine to the incubation saline. Changes in Ca(2+)concentration in the saline and addition of caffeine had no effect on the resting potential of muscle cells. It was hypothesized that signal transduction from norepinephrine-activated membrane adrenoceptors to the ionic pump in earthworm muscle cells depends on influx of extracellular Ca(2+)and subsequent involvement of Ca(2+)-accepting proteins similar to calmodulin in vertebrates.
authors.affiliation: Kazan' State Medical University. emvolkov@kzn.ru
authors.forename: E M
authors.initials: EM
authors.lastname: Volkov
authors.forename: L F
authors.initials: LF
authors.lastname: Nurullin
authors.forename: A S
authors.initials: AS
authors.lastname: Obukhova
authors.forename: A V
authors.initials: AV
authors.lastname: Chikin
authors.forename: E E
authors.initials: EE
authors.lastname: Nikol'skii
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000737:chemistry; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D007477:Ions; D008345:Manganese / Q000378:metabolism; D009132:Muscles / Q000378:metabolism* / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology*; D009835:Oligochaeta; D011941:Receptors, Adrenergic / Q000378:metabolism
chemical_list: D000316:Adrenergic alpha-Agonists; D007477:Ions; D011941:Receptors, Adrenergic; D008345:Manganese; D002118:Calcium; D009638:Norepinephrine