title: Atypical synergistic alpha 1- and beta-adrenergic regulation of adenosine 3',5'-monophosphate and guanosine 3',5'-monophosphate in rat pinealocytes.
abstract: The adrenergic control of cAMP and 3',5'-cyclic GMP (cGMP) in dispersed adult rat pinealocytes was investigated. Norepinephrine treatment increased cAMP and cGMP content 60- and 400-fold, respectively; both alpha- and beta-adrenoceptors had to be activated for these responses to occur. Beta-Adrenergic stimulation alone produced only about 6- and 2-fold increase in cAMP and cGMP content, respectively. Alpha-Adrenergic stimulation, which alone had no effect on either cyclic nucleotide concentration, markedly amplified the beta-adrenergic stimulation of both cAMP and cGMP. The relative potency of alpha-adrenergic agonists and antagonists indicates the alpha 1-subclass of adrenoceptors is involved. A role of alpha 1-adrenoceptors in the control of pineal cAMP is consistent with published evidence of the presence of alpha 1-adrenoceptors on pinealocytes and their role in the regulation of N-acetyltransferase activity and melatonin production.
authors.forename: J
authors.initials: J
authors.lastname: Vanecek
authors.forename: D
authors.initials: D
authors.lastname: Sugden
authors.forename: J
authors.initials: J
authors.lastname: Weller
authors.forename: D C
authors.initials: DC
authors.lastname: Klein
mesh_terms: D000818:Animals; D000242:Cyclic AMP / Q000032:analysis*; D006152:Cyclic GMP / Q000032:analysis*; D004305:Dose-Response Relationship, Drug; D005260:Female; D066298:In Vitro Techniques; D009638:Norepinephrine / Q000494:pharmacology; D010870:Pineal Gland / Q000032:analysis* / Q000187:drug effects; D051381:Rats; D011942:Receptors, Adrenergic, alpha / Q000502:physiology*; D011943:Receptors, Adrenergic, beta / Q000502:physiology*; D013565:Sympatholytics / Q000494:pharmacology; D013566:Sympathomimetics / Q000494:pharmacology; D013997:Time Factors
chemical_list: D011942:Receptors, Adrenergic, alpha; D011943:Receptors, Adrenergic, beta; D013565:Sympatholytics; D013566:Sympathomimetics; D000242:Cyclic AMP; D006152:Cyclic GMP; D009638:Norepinephrine