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Two types of Ca channel in rat pancreatic β-cells

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  • Transport Processes, Metabolism and Endocrinology; Kidney, Gastrointestinal Tract, and Exocrine Glands
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Abstract

Ba currents flowing through single Ca-channels were recorded from cell-attached patches on rat pancreatic ß-cells. Two types of voltage-activated Ca-channels were found. The first (T-type) had a single channel conductance of 8 pS in 100 mM Ba, was activated at a low threshold (around ±50mV) and inactivated by holding potentials positive to ±40 mV. These properties are similar to those described for T-type channels in other preparations. The second type of Ca-channel (L-type) had a single channel conductance of 20pS in 100 mM Ba, was activated at a higher threshold (> ±30mV), showed little inactivation during a 250 ms pulse and could be activated from a holding potential of ±40mV. The dihydropyridine agonist BAYK 8644 selectively prolonged L-type Ca-channel openings. These properties are characteristic of L-type Ca-channels.

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Authors and Affiliations

  1. University Laboratory of Physiology, Parks Road, OX1 3PT, Oxford, UK

    Frances M. Ashcroft, R. P. Kelly & P. A. Smith

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  1. Frances M. Ashcroft
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  2. R. P. Kelly
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  3. P. A. Smith
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Ashcroft, F.M., Kelly, R.P. & Smith, P.A. Two types of Ca channel in rat pancreatic β-cells. Pflügers Arch 415, 504–506 (1990). https://doi.org/10.1007/BF00373633

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  • DOI: https://doi.org/10.1007/BF00373633

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