Beta-adrenergic receptor stimulates L-type calcium current in adult smooth muscle cells.
The hormonal regulation of L-type calcium current was investigated in freshly isolated tracheal smooth muscle cells using the whole-cell configuration of the patch-clamp technique. Isoproterenol stimulated the L-type calcium current 2.6-fold through beta-adrenoceptors. Dialysis of these cells with cyclic AMP, cyclic AMP analogues or the catalytic subunit of cyclic AMP kinase had no effect on basal or isoproterenol-stimulated calcium current. The calcium current was stimulated and inhibited by dialysis of the cells with GTP gamma S and GDP beta S, respectively. Evidently, in some smooth muscle cells the beta-adrenoceptor couples directly to L-type calcium channels via a G protein.
Welling
A
A
II. Physiologisches Institut, Medizinische Fakultät, Universität des Saarlandes, Homburg/Saar, BRD.
Felbel
J
J
Peper
K
K
Hofmann
F
F
D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology; D000818:Animals; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D002417:Cattle; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D003956:Dialysis; D004553:Electric Conductivity; D019204:GTP-Binding Proteins / Q000502:physiology; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000494:pharmacology; D006153:Guanosine Diphosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008564:Membrane Potentials; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology*; D011494:Protein Kinases / Q000378:metabolism; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D013873:Thionucleotides / Q000494:pharmacology; D014132:Trachea / Q000502:physiology
D015220:Calcium Channels; D011943:Receptors, Adrenergic, beta; D013873:Thionucleotides; D006153:Guanosine Diphosphate; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D001498:3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; C023427:guanosine 5'-O-(2-thiodiphosphate); D000255:Adenosine Triphosphate; D000242:Cyclic AMP; D011494:Protein Kinases; D019204:GTP-Binding Proteins; D007545:Isoproterenol