|
rdf:type |
|
|
lifeskim:mentions |
|
|
pubmed:issue |
3
|
|
pubmed:dateCreated |
2000-10-3
|
|
pubmed:abstractText |
The types of Ca(2+)-dependent K(+) channel involved in the prolonged afterhyperpolarization (AHP) in a subgroup of sympathetic neurons have been investigated in guinea pig celiac ganglia in vitro. The conductance underlying the prolonged AHP (gKCa2) was reduced to a variable extent in 100 nM apamin, an antagonist of SK-type Ca(2+)-dependent K(+) channels, and by about 55% in 20 nM iberiotoxin, an antagonist of BK-type Ca(2+)-dependent K(+) channels. The reductions in gKCa2 amplitude by apamin and iberiotoxin were not additive, and a resistant component with an amplitude of nearly 50% of control remained. These data imply that, as well as apamin- and iberiotoxin-sensitive channels, other unknown Ca(2+)-dependent K(+) channels participate in gKCa2. The resistant component of gKCa2 was not abolished by 0.5-10 mM tetraethylammonium, 1 mM 4-aminopyridine, or 5 mM glibenclamide. We also investigated which voltage-gated channels admitted Ca(2+) for the generation of gKCa2. Blockade of Ca(2+) entry through L-type Ca(2+) channels has previously been shown to reduce gKCa2 by about 40%. Blockade of N-type Ca(2+) channels (with 100 nM omega-conotoxin GVIA) and P-type Ca(2+) channels (with 40 nM omega-agatoxin IVA) each reduced the amplitude of gKCa2 by about 35%. Thus Ca(2+) influx through multiple types of voltage-gated Ca(2+) channel can activate the intracellular mechanisms that generate gKCa2. The slow time course of gKCa2 may be explained if activation of multiple K(+) channels results from Ca(2+) influx triggering a kinetically invariant release of Ca(2+) from intracellular stores located close to the membrane.
|
|
pubmed:language |
eng
|
|
pubmed:journal |
|
|
pubmed:citationSubset |
IM
|
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/4-Aminopyridine,
http://linkedlifedata.com/resource/pubmed/chemical/Apamin,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channel Blockers,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Glyburide,
http://linkedlifedata.com/resource/pubmed/chemical/Large-Conductance...,
http://linkedlifedata.com/resource/pubmed/chemical/Peptides,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channel Blockers,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Potassium Channels...,
http://linkedlifedata.com/resource/pubmed/chemical/Small-Conductance...,
http://linkedlifedata.com/resource/pubmed/chemical/Tetraethylammonium,
http://linkedlifedata.com/resource/pubmed/chemical/iberiotoxin,
http://linkedlifedata.com/resource/pubmed/chemical/omega-Agatoxin IVA,
http://linkedlifedata.com/resource/pubmed/chemical/omega-Conotoxin GVIA
|
|
pubmed:status |
MEDLINE
|
|
pubmed:month |
Sep
|
|
pubmed:issn |
0022-3077
|
|
pubmed:author |
|
|
pubmed:issnType |
Print
|
|
pubmed:volume |
84
|
|
pubmed:owner |
NLM
|
|
pubmed:authorsComplete |
Y
|
|
pubmed:pagination |
1346-54
|
|
pubmed:dateRevised |
2006-11-15
|
|
pubmed:meshHeading |
pubmed-meshheading:10980007-4-Aminopyridine,
pubmed-meshheading:10980007-Animals,
pubmed-meshheading:10980007-Apamin,
pubmed-meshheading:10980007-Calcium,
pubmed-meshheading:10980007-Calcium Channel Blockers,
pubmed-meshheading:10980007-Calcium Channels,
pubmed-meshheading:10980007-Female,
pubmed-meshheading:10980007-Ganglia, Sympathetic,
pubmed-meshheading:10980007-Glyburide,
pubmed-meshheading:10980007-Guinea Pigs,
pubmed-meshheading:10980007-Large-Conductance Calcium-Activated Potassium Channels,
pubmed-meshheading:10980007-Male,
pubmed-meshheading:10980007-Membrane Potentials,
pubmed-meshheading:10980007-Neurons,
pubmed-meshheading:10980007-Patch-Clamp Techniques,
pubmed-meshheading:10980007-Peptides,
pubmed-meshheading:10980007-Potassium Channel Blockers,
pubmed-meshheading:10980007-Potassium Channels,
pubmed-meshheading:10980007-Potassium Channels, Calcium-Activated,
pubmed-meshheading:10980007-Small-Conductance Calcium-Activated Potassium Channels,
pubmed-meshheading:10980007-Tetraethylammonium,
pubmed-meshheading:10980007-omega-Agatoxin IVA,
pubmed-meshheading:10980007-omega-Conotoxin GVIA
|
|
pubmed:year |
2000
|
|
pubmed:articleTitle |
Diversity of channels involved in Ca(2+) activation of K(+) channels during the prolonged AHP in guinea-pig sympathetic neurons.
|
|
pubmed:affiliation |
Instituto de Neurociencias, Universidad Miguel Hernández, 03550 Alicante, Spain.
|
|
pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, Non-U.S. Gov't
|
