Beta-adrenergic stimulation of prolactin release from superfused pituitary cell aggregates.
l-Isoproterenol (l-ISO), a specific agonist of beta-adrenergic receptors, evoked a prompt rise of prolactin (PRL) release from superfused anterior pituitary cell aggregates established in culture for 5 days. The effect was concentration-dependent between 1 and 100 nM. d-Isoproterenol was more than 2 orders of magnitude weaker than the l-isomer. When dopamine receptors were blocked with domperidone, PRL secretion was also stimulated by l-epinephrine (E) and l-norepinephrine (NE), the rank order of potency being l-ISO greater than E much greater than NE. Under the latter conditions dopamine and the alpha-adrenergic agonists, clonidine and phenylephrine, had no stimulatory effect at 1 microM. Stimulation of PRL release by l-ISO and E was blocked by the beta-receptor antagonist, propranolol, but not by the alpha-receptor blocker, prazosin.
D000818:Animals; D004837:Epinephrine / Q000494:pharmacology; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000494:pharmacology; D010903:Pituitary Gland, Anterior / Q000187:drug effects / Q000378:metabolism*; D011224:Prazosin / Q000494:pharmacology; D011388:Prolactin / Q000378:metabolism*; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011941:Receptors, Adrenergic / Q000378:metabolism*; D011943:Receptors, Adrenergic, beta / Q000378:metabolism*
D011941:Receptors, Adrenergic; D011943:Receptors, Adrenergic, beta; D011388:Prolactin; D011433:Propranolol; D007545:Isoproterenol; D009638:Norepinephrine; D011224:Prazosin; D004837:Epinephrine