ISSN:
1432-2013
Keywords:
“A-type” K channels
;
4-Aminopyridine
;
Colonic myocytes
;
Patch clamp
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract Two K+ channel populations were identified in depolarized cell-attached membrane patches of myocytes freshly dispersed from the circular smooth muscle of guinea-pig proximal colon. First, a large-conductance (150 pS) Ca2+-activated K+ channel which was non-inactivating and sensitive to blockade by tetraethylammonium (TEA, 0.5–5 mM); and second, a smaller conductance K+ channel which opened and closed within 100 ms, was insensitive to TEA (0.5–5 mM), but was blocked by 5 mM 4-aminopyridine (4-AP) or maintained depolarization, and which had a unitary conductance of 12–13 pS. The averaged time course of these smaller conductance K+ channels closely resembled the time course of the 4-AP-sensitive, Ca2+-insensitive transient outward K+ current recorded in the whole-cell recording mode.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00374307
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