Characteristics and functions of {alpha}-amino-3-hydroxy-5-methyl-4-isoxazolepropionate receptors expressed in mouse pancreatic {alpha}-cells. 2010

Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
Department of Physiology and Biophysics, University of Washington School of Medicine, G-424 Health Science Building, Box 357290, Seattle, Washington 98195-7290, USA.

Pancreatic islet cells use neurotransmitters such as l-glutamate to regulate hormone secretion. We determined which cell types in mouse pancreatic islets express ionotropic glutamate receptor channels (iGluRs) and describe the detailed biophysical properties and physiological roles of these receptors. Currents through iGluRs and the resulting membrane depolarization were measured with patch-clamp methods. Ca(2+) influx through voltage-gated Ca(2+) channels and Ca(2+)-evoked exocytosis were detected by Ca(2+) imaging and carbon-fiber microamperometry. Whereas iGluR2 glutamate receptor immunoreactivity was detected using specific antibodies in immunocytochemically identified mouse alpha- and beta-cells, functional iGluRs were detected only in the alpha-cells. Fast application of l-glutamate to cells elicited rapidly activating and desensitizing inward currents at -60 mV. By functional criteria, the currents were identified as alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate (AMPA) receptors. They were activated and desensitized by AMPA, and were activated only weakly by kainate. The desensitization by AMPA was inhibited by cyclothiazide, and the currents were blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). Islet iGluRs showed nonselective cation permeability with a low Ca(2+) permeability (P(Ca)/P(Na) = 0.16). Activation of the AMPA receptors induced a sequence of cellular actions in alpha-cells: 1) depolarization of the membrane by 27 +/- 3 mV, 2) rise in intracellular Ca(2+) mainly mediated by voltage-gated Ca(2+) channels activated during the membrane depolarization, and 3) increase of exocytosis by the Ca(2+) rise. In conclusion, iGluRs expressed in mouse alpha-cells resemble the low Ca(2+)-permeable AMPA receptor in brain and can stimulate exocytosis.

UI MeSH Term Description Entries
D007150 Immunohistochemistry Histochemical localization of immunoreactive substances using labeled antibodies as reagents. Immunocytochemistry,Immunogold Techniques,Immunogold-Silver Techniques,Immunohistocytochemistry,Immunolabeling Techniques,Immunogold Technics,Immunogold-Silver Technics,Immunolabeling Technics,Immunogold Silver Technics,Immunogold Silver Techniques,Immunogold Technic,Immunogold Technique,Immunogold-Silver Technic,Immunogold-Silver Technique,Immunolabeling Technic,Immunolabeling Technique,Technic, Immunogold,Technic, Immunogold-Silver,Technic, Immunolabeling,Technics, Immunogold,Technics, Immunogold-Silver,Technics, Immunolabeling,Technique, Immunogold,Technique, Immunogold-Silver,Technique, Immunolabeling,Techniques, Immunogold,Techniques, Immunogold-Silver,Techniques, Immunolabeling
D007328 Insulin A 51-amino acid pancreatic hormone that plays a major role in the regulation of glucose metabolism, directly by suppressing endogenous glucose production (GLYCOGENOLYSIS; GLUCONEOGENESIS) and indirectly by suppressing GLUCAGON secretion and LIPOLYSIS. Native insulin is a globular protein comprised of a zinc-coordinated hexamer. Each insulin monomer containing two chains, A (21 residues) and B (30 residues), linked by two disulfide bonds. Insulin is used as a drug to control insulin-dependent diabetes mellitus (DIABETES MELLITUS, TYPE 1). Iletin,Insulin A Chain,Insulin B Chain,Insulin, Regular,Novolin,Sodium Insulin,Soluble Insulin,Chain, Insulin B,Insulin, Sodium,Insulin, Soluble,Regular Insulin
D007608 Kainic Acid (2S-(2 alpha,3 beta,4 beta))-2-Carboxy-4-(1-methylethenyl)-3-pyrrolidineacetic acid. Ascaricide obtained from the red alga Digenea simplex. It is a potent excitatory amino acid agonist at some types of excitatory amino acid receptors and has been used to discriminate among receptor types. Like many excitatory amino acid agonists it can cause neurotoxicity and has been used experimentally for that purpose. Digenic Acid,Kainate,Acid, Digenic,Acid, Kainic
D008297 Male Males
D008564 Membrane Potentials The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization). Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D004594 Electrophysiology The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D005089 Exocytosis Cellular release of material within membrane-limited vesicles by fusion of the vesicles with the CELL MEMBRANE.
D005934 Glucagon A 29-amino acid pancreatic peptide derived from proglucagon which is also the precursor of intestinal GLUCAGON-LIKE PEPTIDES. Glucagon is secreted by PANCREATIC ALPHA CELLS and plays an important role in regulation of BLOOD GLUCOSE concentration, ketone metabolism, and several other biochemical and physiological processes. (From Gilman et al., Goodman and Gilman's The Pharmacological Basis of Therapeutics, 9th ed, p1511) Glucagon (1-29),Glukagon,HG-Factor,Hyperglycemic-Glycogenolytic Factor,Proglucagon (33-61),HG Factor,Hyperglycemic Glycogenolytic Factor
D000200 Action Potentials Abrupt changes in the membrane potential that sweep along the CELL MEMBRANE of excitable cells in response to excitation stimuli. Spike Potentials,Nerve Impulses,Action Potential,Impulse, Nerve,Impulses, Nerve,Nerve Impulse,Potential, Action,Potential, Spike,Potentials, Action,Potentials, Spike,Spike Potential
D000818 Animals Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA. Animal,Metazoa,Animalia

Related Publications

Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
June 1995, Journal of neurochemistry,
Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
July 1995, Neuroscience letters,
Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
August 2007, Journal of neurochemistry,
Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
December 2004, Neuroscience letters,
Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
August 1997, Biochemical Society transactions,
Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
December 1996, Molecular pharmacology,
Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
March 1999, Proceedings of the National Academy of Sciences of the United States of America,
Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
August 1997, Biochemical Society transactions,
Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
March 1992, Molecular pharmacology,
Jung-Hwa Cho, and Liangyi Chen, and Mean-Hwan Kim, and Robert H Chow, and Bertil Hille, and Duk-Su Koh
January 1994, Neuroscience letters,
Copied contents to your clipboard!