title: Stimulation of muscarinic cholinoceptive neurons in the hippocampus evokes a pressor response with bradycardia.
abstract: The injection of neostigmine into the hippocampus of anesthetized rats increased the mean arterial blood pressure (17% of baseline after 60 min injection) and decreased the heart rate (24% of baseline after 60 min injection). These changes were blocked by the co-administration of methylatropine into the hippocampus. Intrahippocampal injection of neostigmine stimulated the secretion of epinephrine and norepinephrine. Adrenodemedullation did not suppress the increase in blood pressure and the decrease in heart rate. It is concluded that the stimulation of muscarinic cholinoceptive neurons in the hippocampus evokes a hypertensive response via an increase in sympathetic drive to the heart and peripheral vasculature, with bradycardia possibly mediated via the parasympathetic system.
authors.affiliation: Third Department of Internal Medicine, Nagoya University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Haruta
authors.forename: A
authors.initials: A
authors.lastname: Iguchi
authors.forename: T
authors.initials: T
authors.lastname: Matsubara
authors.forename: K
authors.initials: K
authors.lastname: Itoh
authors.forename: C L
authors.initials: CL
authors.lastname: Chen
authors.forename: S
authors.initials: S
authors.lastname: Yoshida
authors.forename: R
authors.initials: R
authors.lastname: Terada
authors.forename: M
authors.initials: M
authors.lastname: Kanashiro
authors.forename: O
authors.initials: O
authors.lastname: Suzuki
authors.forename: H
authors.initials: H
authors.lastname: Nishimura
mesh_terms: D000818:Animals; D001286:Atropine Derivatives / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects*; D001919:Bradycardia / Q000503:physiopathology; D004837:Epinephrine / Q000097:blood; D006339:Heart Rate / Q000187:drug effects*; D006624:Hippocampus / Q000187:drug effects*; D007700:Kinetics; D008297:Male; D009388:Neostigmine / Q000494:pharmacology*; D009638:Norepinephrine / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains; D011950:Receptors, Cholinergic / Q000502:physiology; D011976:Receptors, Muscarinic / Q000502:physiology
chemical_list: D001286:Atropine Derivatives; D011950:Receptors, Cholinergic; D011976:Receptors, Muscarinic; D009388:Neostigmine; C006649:methylatropine; D009638:Norepinephrine; D004837:Epinephrine