title: Functional identification and monitoring of individual alpha and beta cells in cultured mouse islets of Langerhans.
abstract: The aim of the present study was to evaluate, by use of fluorescence microscopy and immunofluorescence stainings, the use of a fluorescent membrane potential sensitive probe as a means to identify and monitor changes in membrane potential of individual cell types in whole islets of Langerhans over time. Our work supports the use of the fluorescent probe bis-(1,3 dibutylbarbituric acid) trimethine oxonol (diBAC(4)(3)), in identification of single alpha and beta cells in the periphery of mouse pancreatic islets cultured on extracellular matrix. At a low extracellular glucose concentration (3 mM), heterogeneous staining of the islets was observed. Approximately 97% of the peripheral cells that stained brightly with diBAC(4)(3) were glucagon positive. Additional diBAC(4)(3) studies, demonstrated that an increase in glucose concentration from 3 to 10 mM is paralleled by repolarization of alpha cells and depolarization of beta cells. This suggests that reciprocity of glucagon and insulin release upon glucose stimulation is coupled to divergent changes in membrane potential of these cell types and supports the use of diBAC(4)(3) as a means to detect changes in secretion in both cell types.
authors.affiliation: Department of Hemostasis Biology, Novo Nordisk, Moaloer, Denmark. GHjo@novonordisk.com
authors.forename: G M
authors.initials: GM
authors.lastname: Hjortoe
authors.forename: G M
authors.initials: GM
authors.lastname: Hagel
authors.forename: B R
authors.initials: BR
authors.lastname: Terry
authors.forename: O
authors.initials: O
authors.lastname: Thastrup
authors.forename: P O G
authors.initials: PO
authors.lastname: Arkhammar
mesh_terms: D000818:Animals; D001120:Arginine / Q000494:pharmacology; D001463:Barbiturates; D004305:Dose-Response Relationship, Drug; D005260:Female; D005455:Fluorescent Antibody Technique; D005456:Fluorescent Dyes; D005934:Glucagon / Q000378:metabolism; D005947:Glucose / Q000008:administration & dosage / Q000494:pharmacology; D007515:Islets of Langerhans / Q000166:cytology* / Q000378:metabolism / Q000502:physiology*; D007555:Isoxazoles; D007930:Leucine / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D051379:Mice; D008815:Mice, Inbred Strains; D008856:Microscopy, Fluorescence; D009994:Osmolar Concentration; D013194:Staining and Labeling; D013997:Time Factors; D046509:Tissue Culture Techniques
chemical_list: D001463:Barbiturates; D005456:Fluorescent Dyes; D007555:Isoxazoles; C052795:bis(1,3-dibutylbarbiturate)trimethine oxonol; D005934:Glucagon; D001120:Arginine; D007930:Leucine; D005947:Glucose