Gene expression profiling of human cardiac potassium and sodium channels.
BACKGROUND
The native cardiac ion currents and the action potential itself are the results of the concerted action of several different ion channels. The electrophysiological properties of cardiac cells are determined by the composition of ion channels and by their absolute abundance and proportional ratio.


METHODS
Our aim in this study was to compare the gene expression level of a representative panel of cardiac ion channels with each other and to compare the same channels in the atrium and ventricle of the human heart using quantitative real-time PCR analysis.


RESULTS
We obtained a significant difference in the gene expression levels in 21 of 35 channels between atrium and ventricle of healthy human hearts. Further, we found that the expression levels of Kv1.5 and Kv2.1 transcripts in the ventricle were very high, and that mRNAs for Kv1.7 and Kv3.4 are highly abundant in both the atrium and ventricle, which might indicate a functional role of these ion channel subunits in the formation of action potential in the human ventricle and both in the atrium and ventricle, respectively.


CONCLUSIONS
This is the first report on the expression of several ion channel subunits, such as Kv1.7, Kv3.3 or Kv3.4 in human cardiomyocytes. The expression levels of these genes are comparable with that of well known ion channel subunits. Therefore, it is reasonable to assume, that these ion channel subunits may contribute to native currents in the human myocardium.
Ordög
Balázs
B
Department of Biology, Faculty of Medicine, University of Szeged, Somogyi B. 4. H-6720, Szeged, Hungary.
Brutyó
Endre
E
Puskás
László G
LG
Papp
Julius G
JG
Varró
András
A
Szabad
János
J
Boldogkoi
Zsolt
Z
D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels / Q000378:metabolism; D020869:Gene Expression Profiling; D006325:Heart Atria / Q000378:metabolism*; D006352:Heart Ventricles / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D051666:Kv1.5 Potassium Channel / Q000378:metabolism; D016133:Polymerase Chain Reaction; D015221:Potassium Channels / Q000378:metabolism*; D024683:Potassium Channels, Tandem Pore Domain / Q000378:metabolism; D024642:Potassium Channels, Voltage-Gated / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D051669:Shab Potassium Channels / Q000378:metabolism; D051670:Shaw Potassium Channels / Q000378:metabolism; D015222:Sodium Channels / Q000378:metabolism*
D000072237:ERG1 Potassium Channel; D051638:Ether-A-Go-Go Potassium Channels; C492015:KCNC4 protein, human; C489622:KCNE1 protein, human; C109137:KCNK1 protein, human; D051666:Kv1.5 Potassium Channel; D015221:Potassium Channels; D024683:Potassium Channels, Tandem Pore Domain; D024642:Potassium Channels, Voltage-Gated; D012333:RNA, Messenger; D051669:Shab Potassium Channels; D051670:Shaw Potassium Channels; D015222:Sodium Channels