Single Ca channel currents in mouse pancreatic B-cells.

Journal article

Barium currents flowing through single Ca2+ channels were recorded from outside-out patches isolated from mouse pancreatic B-cells. Only one type of Ca2+ channels was observed. In 110 mM Ba2+, the single channel conductance was 24pS (at negative membrane potentials) and the current amplitude at 0 mV was -0.7 pA. Channel openings were activated by depolarisations more positive than -30 mV and showed little inactivation during 200 ms pulses. Open times were increased by BAY K 8644 an decreased by micromolar Cd2+. Channel activity was subject to rundown in excised patches and little activity remained after 10 min. These properties resemble those of L-type Ca2+ channels in other tissues. It is suggested that this Ca2+ channel participates in the generation of the B-cell action potential and mediates the increase in Ca2+ influx required for insulin secretion.

Authors: Rorsman, P; Ashcroft, F; Trube, G

• Publication status: Published
• Publisher: Springer-Verlag
• Journal: Pflugers Archiv : European journal of physiology
• Volume: 412
• Issue: 6
• Pages: 597-603
• Publication date: 1988-10-01
• DOI: 10.1007/bf00583760
• EISSN: 1432-2013
• ISSN: 0031-6768
• Language: English
• Keywords: Animals; Barium; Cell Membrane; Electric Conductivity; 3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl ester; Islets of Langerhans; Cadmium; Calcium Channels; Action Potentials; Mice