title: Amperometric analysis of exocytosis at chromaffin cells from genetically distinct mice.
abstract: Amperometry is a very powerful technique for investigating the role(s) specific proteins play in exocytosis at the single-cell level. In this study, amperometry has been used to investigate possible changes in exocytosis at chromaffin cells isolated from coloboma and tottering mutant mice. Coloboma mice possess a deletion mutation that encompasses the gene for the presynaptic protein SNAP-25 and tottering mice carry a mutation of the alpha(1A) subunit gene, which encodes the pore-forming region of P/Q-type calcium channels. Although amperometric data measured from tottering and coloboma cells are not significantly different from that measured at wild-type control cells, significant differences are found when groups of wild-type chromaffin cells are analyzed at room temperature and at 37 degrees C. Due to the large variability inherent to amperometric data, it is possible that changes in release resulting from some genetic differences cannot be detected. To fully exploit the technical advantages of using mouse chromaffin cells, experimental guidelines are described which should maximize changes in release resulting from genetic differences and increase the likelihood of detecting a change in amperometric data.
authors.affiliation: Department of Chemistry, 152 Davey Laboratory, The Pennsylvania State University, University Park, PA 16802-6300, USA.
authors.forename: T L
authors.initials: TL
authors.lastname: Colliver
authors.forename: E J
authors.initials: EJ
authors.lastname: Hess
authors.forename: A G
authors.initials: AG
authors.lastname: Ewing
mesh_terms: D000818:Animals; D020865:Calcium Channels, P-Type / Q000172:deficiency / Q000235:genetics; D020907:Calcium Channels, Q-Type / Q000172:deficiency / Q000235:genetics; D002478:Cells, Cultured / Q000378:metabolism; D019439:Chromaffin Cells / Q000378:metabolism*; D004594:Electrophysiology / Q000379:methods*; D005089:Exocytosis / Q000235:genetics*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008817:Mice, Mutant Strains / Q000002:abnormalities* / Q000235:genetics / Q000378:metabolism; D008839:Microelectrodes; D009419:Nerve Tissue Proteins / Q000172:deficiency / Q000235:genetics; D018377:Neurotransmitter Agents / Q000378:metabolism*; D050825:Synaptosomal-Associated Protein 25
chemical_list: D020865:Calcium Channels, P-Type; D020907:Calcium Channels, Q-Type; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D018377:Neurotransmitter Agents; C494209:Snap25 protein, mouse; D050825:Synaptosomal-Associated Protein 25