Synergistic effects in the alpha 1- and beta 1-adrenergic regulations of intracellular calcium levels in striatal astrocytes.
1. Using indo-1 as a calcium fluorescent probe, we have observed the following in striatal astrocytes in primary culture. 2. The stimulation of alpha-adrenoceptors induces a rapid rise in cytosolic calcium resulting from an internal calcium mobilization followed by an external calcium influx (4-min duration). 3. The stimulation of beta 1-adrenoceptors evokes only a slight internal calcium mobilization (90-sec duration). 4. The simultaneous stimulation of beta 1- and alpha 1-adrenoceptors induces a more prolonged calcium influx (10 min). The latter phenomenon could explain the calcium-dependent synergistic effects of alpha 1 and beta stimulation on cAMP production already described in the brain.
Delumeau
J C
JC
Laboratoire de Neuropharmacologie, INSERM U.114, Collège de France, Paris.
Marin
P
P
Cordier
J
J
Glowinski
J
J
Premont
J
J
D000420:Albuterol / Q000494:pharmacology; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003342:Corpus Striatum / Q000166:cytology* / Q000187:drug effects; D004357:Drug Synergism; D015640:Ion Channel Gating / Q000187:drug effects*; D007545:Isoproterenol / Q000494:pharmacology; D008729:Methoxamine / Q000494:pharmacology; D051379:Mice; D009638:Norepinephrine / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects / Q000502:physiology*; D011943:Receptors, Adrenergic, beta / Q000187:drug effects / Q000502:physiology*; D015016:Yohimbine / Q000494:pharmacology
D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D015016:Yohimbine; D011433:Propranolol; D008729:Methoxamine; D007545:Isoproterenol; D000420:Albuterol; D002118:Calcium; D009638:Norepinephrine; D011224:Prazosin