title: Characterization of alpha- and beta-adrenergic agonist stimulation of adenylate cyclase activity in human epidermal keratinocytes in vitro.
abstract: Adrenergic receptors are responsible for selective recognition and binding of catecholamines and may in turn have an effect on epidermal cell growth and maturation via adenosine-3',5'-monophosphate (cAMP). Using endogenous catecholamines and drugs specific for alpha- and beta-receptor subtypes, we have characterized the adrenergic receptor coupled to adenylate cyclase in cultured human epidermal keratinocytes. The relative potency order of stimulation of adenylate cyclase was: isoproterenol greater than epinephrine much greater than norepinephrine. The predominant adrenergic receptor is of the beta 2-subtype, as also confirmed by use of the selective antagonists propranolol, butoxamine, and atenolol. No evidence of alpha-adrenergic receptor mediation of adenylate cyclase was noted with the alpha 2-specific agonist, clonidine. Phenylephrine, the alpha 1-specific agonist, affected cAMP formation but this response could not be totally inhibited with prazosin, suggesting an unknown mechanism of action. Human keratinocytes retained the same beta-adrenergic receptor potency order properties throughout growth and maturation.
mesh_terms: D000262:Adenylyl Cyclases / Q000378:metabolism*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D000078404:Epidermal Cells; D004817:Epidermis / Q000187:drug effects; D004837:Epinephrine / Q000494:pharmacology; D005260:Female; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D008875:Middle Aged; D009638:Norepinephrine / Q000494:pharmacology; D011941:Receptors, Adrenergic / Q000145:classification*; D011942:Receptors, Adrenergic, alpha / Q000145:classification*; D011943:Receptors, Adrenergic, beta / Q000145:classification*
chemical_list: D011941:Receptors, Adrenergic; D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D009638:Norepinephrine; D004837:Epinephrine