title: L-phenylisopropyladenosine (L-PIA) diminishes halothane anesthetic requirements and decreases noradrenergic neurotransmission in rats.
abstract: The effect of L-phenylisopropyladenosine (L-PIA), the A1 adenosine agonist, on the depth of anesthesia was investigated in halothane-anesthetized rats. L-PIA treatment reduced the minimum anesthetic concentration (MAC) of halothane that prevented 50% of animals from moving in response to a painful stimulus by 49%. MAC experiments performed with L-PIA given in conjunction with A1 adenosine receptor antagonists which either permeate the blood-brain barrier (8-phenyltheophylline [8-PT] or do not (8-sulphophenyltheophylline [8-So-PT]) indicate that central mechanisms are involved. Noradrenergic neurotransmission was diminished following L-PIA administration in halothane-anesthetized rats in all brain regions. These data suggest that acute L-PIA treatment decreases central noradrenergic neurotransmission and may represent the mechanism for the decrease in halothane dose to achieve an anesthetic endpoint anesthetic response to halothane.
authors.affiliation: Department of Anesthesia, Stanford University School of Medicine, Palo Alto, CA.
authors.forename: B D
authors.initials: BD
authors.lastname: Birch
authors.forename: G L
authors.initials: GL
authors.lastname: Louie
authors.forename: R G
authors.initials: RG
authors.lastname: Vickery
authors.forename: D M
authors.initials: DM
authors.lastname: Gaba
authors.forename: M
authors.initials: M
authors.lastname: Maze
mesh_terms: D000241:Adenosine / Q000031:analogs & derivatives*; D000758:Anesthesia; D000818:Animals; D001921:Brain / Q000187:drug effects / Q000502:physiology; D006221:Halothane / Q000008:administration & dosage*; D008297:Male; D009638:Norepinephrine / Q000502:physiology*; D010660:Phenylisopropyladenosine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D009435:Synaptic Transmission / Q000187:drug effects*; D013806:Theophylline / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D010660:Phenylisopropyladenosine; C031433:8-(4-sulfophenyl)theophylline; D013806:Theophylline; C028322:8-phenyltheophylline; D000241:Adenosine; D006221:Halothane; D009638:Norepinephrine