title: Presynaptic facilitation of excitatory postsynaptic potential by glucagon in neurons of rat ventromedial hypothalamic slices.
abstract: Intracellular recordings were made from neurons in rat ventromedial hypothalamus (VMH), in vitro. Application of glucagon (100 nM to 5 microM) for 2-5 min increased the amplitude of excitatory postsynaptic potential (EPSP) lasting for 10-20 min. Forskolin and 8-bromo-cyclic AMP mimicked glucagon in producing a long-lasting facilitation of the EPSP. These drugs did not affect depolarizing response produced by glutamate. 3-Isobutyl-1-methylxanthine (IBMX) potentiated the time course of glucagon-induced facilitation of the EPSP. These results suggest that glucagon facilitates the EPSP probably by increasing transmitter release through activation of adenylate cyclase.
authors.affiliation: Department of Physiology, Kurume University School of Medicine, Japan.
authors.forename: S
authors.initials: S
authors.lastname: Shoji
authors.forename: T
authors.initials: T
authors.lastname: Akasu
authors.forename: K
authors.initials: K
authors.lastname: Nonaka
mesh_terms: D000818:Animals; D000242:Cyclic AMP / Q000502:physiology; D004594:Electrophysiology; D005934:Glucagon / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D009474:Neurons / Q000502:physiology*; D051381:Rats; D011921:Rats, Inbred WKY; D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface / Q000502:physiology; D013569:Synapses / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects; D014697:Ventromedial Hypothalamic Nucleus / Q000502:physiology*
chemical_list: D017459:Receptors, Amino Acid; D011956:Receptors, Cell Surface; D005934:Glucagon; D000242:Cyclic AMP