Internal perfusion of guinea‐pig hepatocytes with buffered Ca2+ or inositol 1,4,5‐trisphosphate mimics noradrenaline activation of K+ and Cl− conductances

FEBS Letters

Capiod, T.¹  Sandford, Christine A.¹  Ogden, D.C.¹  Field, Anne C.¹ 

[1] MRC Receptor Mechanisms Research Group, Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, England

关键词: Hepatocyte;    Noradrenaline;    Apamin;    Ca2+ activation;    K+ conductance;    Cl− conductance;    Inositol 1;    4;    5-trisphosphate;    BAPTA;    1;    2-bis(2-aminophenoxy)-eth -ane-N;    N;    N′;    N′-tetraacetic acid;   

DOI  :  10.1016/0014-5793(87)80672-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

External application of noradrenaline to voltage-clamped guinea-pig isolated hepatocytes evoked membrane conductance increases to K⁺ and Cl⁻. This effect was reproduced by internal perfusion of the cells with 2 μM buffered Ca²⁺ and with 20 μM inositol 1,4,5-trisphosphate (IP₃). The kinetic properties of the K⁺ conductance and its selective block by the toxin apamin were the same in each case. Cyclical fluctuations of conductance observed with noradrenaline were reproduced by internal IP₃ but not by Ca²⁺ perfusion, indicating that oscillations of intracellular free Ca²⁺ may arise from properties of the Ca²⁺ sequestration mechanism at constant IP₃ concentration.

【 授权许可】

Unknown