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Selective downregulation of an inactivating K+ conductance by analogues of cAMP in mouse Schwann cells.
Author(s) -
Despeyroux S,
Beaudu-Lange C,
Coles J A,
Amédée T
Publication year - 1997
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1997.sp021958
Subject(s) - downregulation and upregulation , conductance , chemistry , microbiology and biotechnology , skin conductance , biophysics , neuroscience , biology , medicine , biochemistry , physics , biomedical engineering , gene , condensed matter physics
1. Voltage‐dependent K+ conductances on Schwann cells in organotypic cultures of mouse dorsal root ganglia were classified as inactivating or sustained (responsible for currents IA and IK, respectively). IA is known to be much reduced on Schwann cells that contact neurites. 2. In the absence of neurones, IA and IK were present. IA, but not IK, was markedly reduced (by 80% after 105 h of treatment) by 2 mM 8‐(4‐chlorophenylthio)‐cAMP (cpt‐cAMP), a weakly hydrolysable analogue of cAMP. The effect did not appear for at least 2 h and was maximal after about 100 h. 3. The effect of 1 mM cpt‐cAMP was abolished in the presence of an inhibitor of protein kinases, N‐[2‐bromocinnamyl(amino)ethyl]‐5‐isoquinolinesulphonamide (H‐89, 10 microM). 4. Other analogues of cAMP, but not an analogue of cGMP (8‐bromo‐cGMP), also reduced IA. 5. We conclude that IA, but not IK, can be downregulated by activation of the protein kinase A pathway.