Cyclic AMP and alpha-receptor-mediated modulation of noradrenaling release from rat brain slices.
Oxymetazoline (an alpha-receptor agonist) reduced and phentolamine (an alpha-receptor antagonist) increased depolarization-induced release (potassium or electrical field stimulation) of 3H-noradrenaline (NA) from superfused neocortical slices in a dose-dependent way. Inhibition of phosphodiesterase also reduced NA release; this effect could be reversed by phentolamine. Phosphodiesterase inhibition potentiated the effect of oxymetazoline. It is suggested that stimulation of presynaptic alpha-receptors may reduce NA release up to about 60% and that increased cyclic AMP formation might be involved in this modulation.
D000818:Animals; D001921:Brain / Q000378:metabolism*; D000242:Cyclic AMP / Q000378:metabolism*; D003975:Diazepam / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D066298:In Vitro Techniques; D008297:Male; D009638:Norepinephrine / Q000378:metabolism*; D010109:Oxymetazoline / Q000494:pharmacology; D010643:Phenoxybenzamine / Q000494:pharmacology; D010646:Phentolamine / Q000494:pharmacology; D010726:Phosphodiesterase Inhibitors; D051381:Rats; D011941:Receptors, Adrenergic / Q000187:drug effects*; D011942:Receptors, Adrenergic, alpha / Q000187:drug effects*; D009435:Synaptic Transmission / Q000187:drug effects; D014970:Xanthines / Q000494:pharmacology
D010726:Phosphodiesterase Inhibitors; D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D014970:Xanthines; D010643:Phenoxybenzamine; D010109:Oxymetazoline; D000242:Cyclic AMP; D003975:Diazepam; D009638:Norepinephrine; D010646:Phentolamine