ISSN:
1432-1424
Keywords:
FDC-P2
;
interleukin 3
;
voltage-dependent K+ channel
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Chemistry and Pharmacology
Notes:
Summary The electrical properties of a mouse interleukin (IL)-3-dependent cell line, FDC-P2, were examined using the tightseal whole-cell clamp technique. Under current clamp conditions with 140mM K+ in the pipette, the cells had a resting potential of ∼−30 mV. Under voltage-clamp conditions, a transient outward current was elicited upon depolarization from a holding potential of −80 mV. The current was activated at potentials more positive than −10 mV and had a delayed-rectifying property. It showed rapid activation and slow inactivation during command steps. The current was abolished by Cs+ in the pipette, indicating that K+ is the charge carrier. The K+ current was suppressed by tetraethylammonium withK i of 〈0.1mM and was not affected by scorpion toxin. Recovery from inactivation was steeply voltage dependent: As the holding potential was more hyperpolarized, the recovery became faster. Thus, with a holding potential of −80 mV, the current showed slight use-dependent inactivation, while the current decreased prominently by repetitive depolarization at a holding potential of −40 mV. These properties of the K+ current are similar to those of thel-type K+ channel current in mature T lymphocytes. The K+ current in FDC-P2 cells was dramatically reduced after culture in the IL-3-free medium for 1–2 days. When IL-3 was re-added to the medium, the current was re-expressed. These observations suggest that expression of the K+ current depends on extracellular IL-3, and that the current may play some roles in proliferation of these cells.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01872401
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