Dopamine induces intracellular Ca2+ signals mediated by alpha1B-adrenoceptors in rat pineal cells.
We have studied the functional interaction of dopamine with alpha1-adrenoceptor subtypes by measuring intracellular Ca2+ levels in pineal cells, a cell type where adrenoceptors are well characterized. We show that dopamine induces transient intracellular Ca2+ signals in only 70% of cells responding to phenylephrine. Dopamine-induced Ca2+ signals desensitise faster than Ca2+ transients elicited with phenylephrine and are selectively blocked by desipramine, imipramine, and alpha1B-adrenoceptor antagonists. These results suggest that dopamine induced Ca2+ signals are mainly due to the activation of one subtype of alpha-adrenoceptor, the alpha1B.
Rey
E
E
Department of Physiology and Biophysics, School of Medicine, University of Seville, Avda. Sánchez Pizjuán, 4, 41009, Seville, Spain.
Hernández-Díaz
F J
FJ
Abreu
P
P
Alonso
R
R
Tabares
L
L
D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004298:Dopamine / Q000494:pharmacology*; D018491:Dopamine Agonists / Q000494:pharmacology; D008297:Male; D010656:Phenylephrine / Q000494:pharmacology; D010870:Pineal Gland / Q000187:drug effects* / Q000378:metabolism; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D018340:Receptors, Adrenergic, alpha-1 / Q000187:drug effects*; D017983:Receptors, Catecholamine / Q000037:antagonists & inhibitors; D015398:Signal Transduction
C547718:Adra1b protein, rat; D058668:Adrenergic alpha-1 Receptor Antagonists; D000317:Adrenergic alpha-Antagonists; D018491:Dopamine Agonists; D018340:Receptors, Adrenergic, alpha-1; D017983:Receptors, Catecholamine; D010656:Phenylephrine; D002118:Calcium; D004298:Dopamine; D011224:Prazosin