Linked Life Data

8608860

Source:http://linkedlifedata.com/resource/pubmed/id/8608860

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-5-30
pubmed:abstractText
Calcium influx is known to be prerequisite for membrane fusion of myoblasts. However, little is known about the channels that are responsible for the entry of calcium into the cells. Here we show that K(Ca) channels and stretch-activated channels are involved in the calcium influx. Upon analysis of single-channel recordings, calcium sensitivity of K(Ca) channels in myoblasts was found to be about sixfold higher than that in myotubes. Their density in myoblasts (1.68 micron(-2)) was also about sixfold higher than that in myotubes (0.27 micron(-2)). In addition, the opening of the calcium-permeable cationic channels in myoblasts was found to increase with membrane stretching and could be blocked by gadolinium. The density of stretch-activated channels was 0.22 micron(-2) for myoblasts, and the relative permeability of calcium to potassium was P(Ca)/P(K) approximately 3.6. The channels could generate inward calcium currents to open K(Ca) channels in physiological solution. Furthermore, the activation of K(Ca) channels by phloretin dramatically hyperpolarized the resting membrane potential of myoblasts and this effect could be reversed upon treatment of tetraethylammonium. While phloretin induced precocious fusion, tetraethylammonium or gadolinium blocked not only the phloretin-induced precocious fusion but also the spontaneous fusion of myoblasts. These results suggest that hyperpolarization generated by reciprocal activation of stretch-activated channels and K(Ca) channels is involved in the calcium influx that triggers myoblast fusion.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0012-1606
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
175
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
14-23
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Involvement of K(Ca) channels and stretch-activated channels in calcium influx, triggering membrane fusion of chick embryonic myoblasts.
pubmed:affiliation
Department of Molecular Biology, College of Natural Sciences, Seoul, Korea.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't