Inhibitory effect of norepinephrine on immunoreactive corticotropin-releasing factor release from the rat hypothalamus in vitro.
Effects of catecholamines on immunoreactive corticotropin-releasing factor (I-CRF) release from the rat hypothalamus were examined using a rat hypothalamic perifusion system and a rat CRF RIA in vitro. Norepinephrine had a potent inhibitory effect on I-CRF release in a dose-dependent manner at 0.1 nM-1 microM concentrations, but dopamine did not. This inhibitory effect of norepinephrine was completely blocked by propranolol, but only partially blocked by phentolamine. Isoproterenol also had a potent inhibitory effect at 0.01-100 nM concentrations, and a high dose of phenylephrine (10 nM) inhibited I-CRF release. Clonidine did not influence I-CRF release. These results suggest that norepinephrine inhibits I-CRF release mainly through the beta-adrenergic receptor and partially through the alpha 1-receptor.
D000322:Adrenergic Agonists / Q000494:pharmacology*; D000818:Animals; D003000:Clonidine / Q000494:pharmacology; D003346:Corticotropin-Releasing Hormone / Q000378:metabolism*; D004298:Dopamine / Q000494:pharmacology; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology*; D010646:Phentolamine / Q000494:pharmacology; D010656:Phenylephrine / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011863:Radioimmunoassay; D051381:Rats; D011919:Rats, Inbred Strains
D000322:Adrenergic Agonists; D010656:Phenylephrine; D003346:Corticotropin-Releasing Hormone; D011433:Propranolol; D007545:Isoproterenol; D003000:Clonidine; D004298:Dopamine; D009638:Norepinephrine; D010646:Phentolamine