Osmosensitivity of an inwardly rectifying chloride current revealed by whole‐cell and perforated‐patch recordings in cultured rat cortical astrocytes

FEBS Letters

Fava, Marianna²  Nobile, Mario²  Ferroni, Stefano¹ 

[1]Department of Human and General Physiology, University of Bologna, Via San Donato 19/2, 40127 Bologna, Italy

[2]Institute of Cybernetics and Biophysics, CNR, Via De Marini 6, 16149 Genoa, Italy

关键词: Astroglia;    ClC-2 channel;    Perforated patch;    Osmoregulation;    Regulatory volume decrease;    dbcAMP;    dibutyryl cyclic AMP;    DMSO;    dimethyl sulfoxide;    EGTA;    ethylene glycol-bis(β-aminoethyl ether)-N;    N;    N′;    N′;    -tetraacetic acid;    NMDG+;    N-methyl-D-glucamine;    RVD;    regulatory volume decrease;    TES;    N-tris[hydroxymethyl]methyl-2-aminoethanesulfonic acid;   

DOI  :  10.1016/S0014-5793(01)02221-9

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The osmosensitivity of the inwardly rectifying Cl⁻ current (I _Clh), expressed by primary cultured rat neocortical astrocytes long-term treated with dibutyryl cyclic AMP, was investigated in the whole-cell and perforated-patch modes. In whole-cell experiments, whereas hypotonic extracellular solution (Δ=100 mOsmol) did not cause any change in I _Clh, hypertonicity produced a slowly developing, ∼40% reversible decrease in current magnitude. By contrast, in perforated-patch experiments, exposure to a less hypertonic saline (Δ=50 mOsmol) depressed the current to ∼50%, and hypotonicity induced a ∼50% slow increase in I _Clh. These differences in osmosensitivity between the two experimental modes suggest that the osmoregulation of I _Clh may be mediated by complex intracellular mechanism(s), which appear(s) to be partly compromised by the dialysis of the astrocytic cytoplasm.

【 授权许可】

Unknown