Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10768892 | Biochemical and Biophysical Research Communications | 2005 | 6 Pages |
Abstract
The actions of the ciliary neurotrophic factor (CNTF) were assessed on adult mouse skeletal muscle L-type Ca2+ currents and on Ca2+ release from sarcoplasmic reticulum. Currents were measured with the whole cell patch clamp technique. Ca2+ signals in response to single action potentials were recorded with Fluo3-AM. CNTF (20Â ng/ml) reversibly reduced the amplitude of Ca2+ channel currents by 50% within 15Â min. In addition, CNTF greatly increased the rate of inactivation during depolarizing pulses and shifted the steady state inactivation curve by â12Â mV. The effects of CNTF were mimicked by the PKC activator PMA and prevented by the PKC-inhibitor chelerythrine. In contrast to the effects on the Ca2+ conductance, charge movement and Ca2+ signals remained unaffected by CNTF. These results suggest that CNTF can rapidly decrease muscle Ca2+ channel currents by promoting inactivation, probably through an intracellular PKC-dependent mechanism.
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Authors
Daniel Zaldivar, MarÃa C. GarcÃa, Jorge A. Sánchez,