title: Alpha 2-adrenergic receptors decrease DNA replication and cell proliferation and induce neurite outgrowth in transfected rat pheochromocytoma cells.
abstract: Alpha 2-adrenergic receptors (alpha(2)-ARs) have a widespread distribution in the central nervous system (CNS) and affect a number of biochemical and behavioral functions, including stimulation of prefrontal cortex (PFC) and cognitive function. In addition to its role as a classical neurotransmitter, norepinephrine (NE) has been recently shown to exert an important influence on the plasticity in areas of the brain where neurogenesis persists in the adult, notably the subgranular zone (SGZ) within the dentate gyrus of the hippocampus and the olfactory bulb (OB). In regulating adult neurogenesis, the noradrenergic system is functionally integrated with chronic stress and depression. Chronic stress, depression, or depletion of NE in vivo suppress, and antidepressant treatments induce hippocampal neurogenesis by down- or upregulating, respectively, cell proliferation. In the present study we show that alpha(2)-AR subtypes promote the differentiation rather than cell proliferation of PC12 cells. It is conceivable that alpha(2)-ARs might contribute neurotrophic actions in vivo synergistically or in permutation with other neurotrophic factors.
authors.affiliation: Department of Pharmacology, School of Medicine, University of Patras-Rion, GR-26504, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Karkoulias
authors.forename: O
authors.initials: O
authors.lastname: Mastrogianni
authors.forename: I
authors.initials: I
authors.lastname: Ilias
authors.forename: A
authors.initials: A
authors.lastname: Lymperopoulos
authors.forename: S
authors.initials: S
authors.lastname: Taraviras
authors.forename: N
authors.initials: N
authors.lastname: Tsopanoglou
authors.forename: N
authors.initials: N
authors.lastname: Sitaras
authors.forename: C S
authors.initials: CS
authors.lastname: Flordellis
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D004261:DNA Replication / Q000502:physiology*; D004837:Epinephrine / Q000494:pharmacology; D006801:Humans; D016501:Neurites / Q000502:physiology*; D009474:Neurons / Q000502:physiology* / Q000648:ultrastructure; D016716:PC12 Cells; D051381:Rats; D018341:Receptors, Adrenergic, alpha-2 / Q000235:genetics* / Q000378:metabolism; D014162:Transfection
chemical_list: D000316:Adrenergic alpha-Agonists; D018341:Receptors, Adrenergic, alpha-2; D004837:Epinephrine