Linked Life Data

11294242

Source:http://linkedlifedata.com/resource/pubmed/id/11294242

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2001-4-10
pubmed:databankReference
pubmed:abstractText
The relationship between the density of ionic currents through major two channels, voltage-dependent L-type Ca2+ channels (L-type VDCC) and large-conductance, Ca2+-activated K+ channels (BKC), and the mRNA expression levels of alpha1C subunit of L-type VDCC (alpha1C) and alpha/beta subunits of BKC (alphaBK/betaBK) were compared in smooth muscle cells (SMC) of rabbit aorta and vas deferens using whole cell-voltage clamp and reverse transcription-polymerase chain reaction (RT-PCR) analyses. The density of the currents through VDCC (ICa) and BKC (IK,Ca) at +10 mV in aortic SMC was approximately one-seventh and one-sixth respectively of that in vas deferens. Whilst application of the Ca2+ channel agonist Bay K 8644 increased ICa by 75-90% in these SMC, the increase in IK,Ca was far greater in aorta than in vas deferens. The expression of the alpha1C transcript in vas deferens was approximately 3.5 times higher than that in aorta. In contrast, expression of alphaBK/betaBK was almost identical in both tissues, indicating the dissociation of IK,Ca density from the expression levels of BKC transcripts in aorta. The results were supported by Western blot and immunocytochemical analyses using subunit-specific antibodies. The lower Ca2+ influx through VDCC in aorta activates only a very limited fraction of BKC compared with that in vas deferens. The greater expression of BKC than of VDCC in aortic SMC contributes to a strong negative feed-back mechanism that minimizes membrane depolarization and acts as a safety margin to maintain low membrane excitability.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
441
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
611-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:11294242-3-Pyridinecarboxylic acid..., pubmed-meshheading:11294242-Amino Acid Sequence, pubmed-meshheading:11294242-Animals, pubmed-meshheading:11294242-Aorta, pubmed-meshheading:11294242-Blotting, Western, pubmed-meshheading:11294242-Calcium, pubmed-meshheading:11294242-Calcium Channel Agonists, pubmed-meshheading:11294242-Calcium Channels, L-Type, pubmed-meshheading:11294242-Cloning, Molecular, pubmed-meshheading:11294242-Gene Expression, pubmed-meshheading:11294242-Large-Conductance Calcium-Activated Potassium Channels, pubmed-meshheading:11294242-Male, pubmed-meshheading:11294242-Membrane Potentials, pubmed-meshheading:11294242-Molecular Sequence Data, pubmed-meshheading:11294242-Muscle, Smooth, Vascular, pubmed-meshheading:11294242-Potassium, pubmed-meshheading:11294242-Potassium Channels, pubmed-meshheading:11294242-Potassium Channels, Calcium-Activated, pubmed-meshheading:11294242-RNA, Messenger, pubmed-meshheading:11294242-Rabbits, pubmed-meshheading:11294242-Reverse Transcriptase Polymerase Chain Reaction, pubmed-meshheading:11294242-Tetraethylammonium, pubmed-meshheading:11294242-Transcription, Genetic, pubmed-meshheading:11294242-Vas Deferens
pubmed:year
2001
pubmed:articleTitle
Comparative study of the molecular and functional expression of L-type Ca2+ channels and large-conductance, Ca2+-activated K+ channels in rabbit aorta and vas deferens smooth muscle.
pubmed:affiliation
Department of Molecular and Cellular Pharmacology, Faculty of Pharmaceutical Sciences, Nagoya City University, Mizuhoku, Japan.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't