Catecholamine secretion from the rabbit adrenal gland is not modulated by a mechanism involving beta-adrenoceptors.
The possibility that catecholamine secretion from the rabbit adrenal gland is subject to modulation by a mechanism involving beta-adrenoceptors was investigated in an isolated perfused preparation of the gland. The adrenal catecholamine stores were radiolabelled with 3H-adrenaline and subsequently efflux of radioactivity was elicited by stimulation of an attached branch of the splanchnic nerve. The efflux of radioactivity evoked by nerve stimulation (1 min at 5 Hz) was not altered by isoprenaline (0.1 microM), metroprolol (0.1 microM) or (+/-)-propranolol (1 microM). Stimulation-induced efflux was reduced in the presence of a higher concentration of (+/-)-propranolol (10 microM); however, it was also reduced by (+)-propranolol (10 microM). These findings do not support the existence in the rabbit adrenal gland of a mechanism involving beta-adrenoceptors through which catecholamine secretion may be modulated.
D000311:Adrenal Glands / Q000378:metabolism*; D000818:Animals; D002395:Catecholamines / Q000378:metabolism*; D004558:Electric Stimulation; D004837:Epinephrine / Q000494:pharmacology; D005246:Feedback; D066298:In Vitro Techniques; D007545:Isoproterenol / Q000494:pharmacology; D008790:Metoprolol / Q000494:pharmacology; D011433:Propranolol / Q000494:pharmacology; D011817:Rabbits; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D013153:Splanchnic Nerves / Q000502:physiology
D002395:Catecholamines; D011943:Receptors, Adrenergic, beta; D011433:Propranolol; D008790:Metoprolol; D007545:Isoproterenol; D004837:Epinephrine