title: Guanfacine enhances cardiac acetylcholine release with little effect on norepinephrine release in anesthetized rabbits.
abstract: An α2A-adrenergic agonist guanfacine improves autonomic imbalance in attention-deficit hyperactivity disorder, suggesting that it may be useful to correct autonomic imbalance in chronic heart failure (CHF) patients. To investigate the effects of guanfacine on cardiac autonomic nerve activities, a microdialysis technique was applied to anesthetized rabbit heart. Acetylcholine (ACh) and norepinephrine (NE) concentrations in atrial dialysates were measured as indices of cardiac autonomic nerve activities. Guanfacine at a dose of 100 μg/kg significantly decreased heart rate and increased dialysate ACh concentration without decreasing sympathetic NE release. Guanfacine may be useful for vagal activation therapy in CHF patients.
authors.affiliation: Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan. Electronic address: shujismz@ri.ncvc.go.jp.
authors.forename: Shuji
authors.initials: S
authors.lastname: Shimizu
authors.affiliation: Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Kawada
authors.affiliation: Department of Cardiac Physiology, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Akiyama
authors.affiliation: Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan.
authors.forename: Michael James
authors.initials: MJ
authors.lastname: Turner
authors.affiliation: Department of Research Promotion and Management, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan.
authors.forename: Toshiaki
authors.initials: T
authors.lastname: Shishido
authors.affiliation: Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan.
authors.forename: Atsunori
authors.initials: A
authors.lastname: Kamiya
authors.affiliation: Department of Cardiac Physiology, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan.
authors.forename: Mikiyasu
authors.initials: M
authors.lastname: Shirai
authors.affiliation: Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, Osaka 565-8565, Japan.
authors.forename: Masaru
authors.initials: M
authors.lastname: Sugimachi
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D058647:Adrenergic alpha-2 Receptor Agonists / Q000494:pharmacology*; D000758:Anesthesia; D000818:Animals; D004305:Dose-Response Relationship, Drug; D016316:Guanfacine / Q000494:pharmacology*; D006321:Heart / Q000187:drug effects / Q000294:innervation; D006339:Heart Rate / Q000187:drug effects; D017551:Microdialysis; D009206:Myocardium / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism*; D011817:Rabbits; D014628:Vagotomy; D014630:Vagus Nerve / Q000378:metabolism*
chemical_list: D058647:Adrenergic alpha-2 Receptor Agonists; D016316:Guanfacine; D000109:Acetylcholine; D009638:Norepinephrine
keywords: Acetylcholine; Guanfacine; Microdialysis; Norepinephrine; α(2)-Adrenergic agonist