title: Involvement of the hippocampus in central nervous system-mediated glucoregulation in rats.
abstract: To find out whether the hippocampus is involved in central nervous system-mediated glucoregulation, we injected saline, neostigmine, dopamine, norepinephrine, bombesin, beta-endorphin, somatostatin, and prostaglandin F2 alpha into the dorsal hippocampus in anesthetized fed rats. After injection of dopamine, norepinephrine, bombesin, beta-endorphin, somatostatin, or prostaglandin F2 alpha, the level of hepatic venous plasma glucose did not differ from that in saline-treated control rats. However, neostigmine, an inhibitor of acetylcholine esterase, caused a dose-dependent increase in the hepatic venous plasma glucose concentration. This neostigmine-induced hyperglycemia was dose-dependently suppressed by coadministration of atropine, but not by hexamethonium. Injection of neostigmine (5 X 10(-8) mol) resulted in an increase not only in glucose but also in glucagon, epinephrine, and norepinephrine in hepatic venous plasma. In bilateral adrenalectomized rats, neostigmine-induced hyperglycemia was suppressed, but the hepatic venous plasma glucose concentration still increased significantly. These results indicate that the hippocampus is involved in central nervous system-mediated glucoregulation through cholinergic muscarinic activation, partly via epinephrine secretion.
authors.affiliation: Third Department of Internal Medicine, Nagoya University School of Medicine, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Uemura
authors.forename: A
authors.initials: A
authors.lastname: Iguchi
authors.forename: A
authors.initials: A
authors.lastname: Yatomi
authors.forename: H
authors.initials: H
authors.lastname: Miura
authors.forename: A
authors.initials: A
authors.lastname: Honmura
authors.forename: M
authors.initials: M
authors.lastname: Yanase
authors.forename: N
authors.initials: N
authors.lastname: Sakamoto
mesh_terms: D000315:Adrenalectomy; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002490:Central Nervous System / Q000502:physiology*; D005947:Glucose / Q000378:metabolism*; D006624:Hippocampus / Q000502:physiology*; D006728:Hormones / Q000097:blood; D008102:Liver Circulation; D008297:Male; D009388:Neostigmine / Q000494:pharmacology; D018377:Neurotransmitter Agents / Q000494:pharmacology; D009994:Osmolar Concentration; D051381:Rats; D011919:Rats, Inbred Strains; D014680:Veins
chemical_list: D001786:Blood Glucose; D006728:Hormones; D018377:Neurotransmitter Agents; D009388:Neostigmine; D005947:Glucose