Beta 2-adrenoceptor-mediated increase in the slow inward calcium current in atrial cells.
The effects of procaterol (beta 2-adrenoceptor agonist) on the slow inward calcium current (Isi) were examined in single cells of guinea-pig heart. Procaterol increased Isi in atrial cells, in the presence of atenolol (beta 1-adrenoceptor antagonist). The effect was abolished by ICI-118551 (beta 2-adrenoceptor antagonist). However, procaterol did not modify the membrane currents in ventricular cells. These results suggest that beta 2-adrenoceptor agonists bind to beta 2-adrenoceptors in atrial cells and augment Isi, but beta 2-adrenoceptors are not present in ventricular cells.
Iijima
T
T
Department of Pharmacology, Tohoku University School of Medicine, Sendai, Japan.
Taira
N
N
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000420:Albuterol / Q000494:pharmacology; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects*; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D004983:Ethanolamines / Q000494:pharmacology; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects; D066298:In Vitro Techniques; D009206:Myocardium / Q000166:cytology / Q000378:metabolism*; D017265:Procaterol; D011412:Propanolamines / Q000494:pharmacology; D011943:Receptors, Adrenergic, beta / Q000502:physiology*
D000316:Adrenergic alpha-Agonists; D015220:Calcium Channels; D004983:Ethanolamines; D011412:Propanolamines; D011943:Receptors, Adrenergic, beta; C026777:ICI 118551; D000420:Albuterol; D017265:Procaterol