Noradrenaline inhibits depolarization-induced 3H-serotonin release from slices of rat hippocampus.
The depolarization (26 mM K+)-induced release of 3H-serotonin and 3H-noradrenaline from slices of rat hippocampus was studied with a superfusion method. Exogenous NA (in the presence of 10 muM desipramine) inhibited 3H-5-HT release (EC50 3 X 10(-7) M) as well as 3H-NA release (EC50 10(-7) M) by more than 70%. Both of these effects were competitively antagonized by phentolamine, but not by propranolol. It is tentatively suggested that the inhibitory effect of NA on 3H-5-HT release from hippocampus slices reflects the activation of postsynaptic alpha-receptors which are localized on serotonergic nerve terminals.
D000818:Animals; D004305:Dose-Response Relationship, Drug; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000378:metabolism / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology; D011188:Potassium / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects; D012701:Serotonin / Q000378:metabolism*
D011942:Receptors, Adrenergic, alpha; D012701:Serotonin; D011433:Propranolol; D007545:Isoproterenol; D011188:Potassium; D009638:Norepinephrine; D010646:Phentolamine