Cardiac gap junction channels: modulation of expression and channel properties.
In the heart, intercellular gap junction channels constructed from connexin molecules are crucial for conduction of the electric impulse. Cardiomyocytes can be interconnected by channels composed of three types of connexin proteins: Cx40, Cx43 or Cx45. In mammalian hearts, these three isoforms are regionally differently expressed and even between the species differences exist. Each of these channel-types possesses specific properties and are susceptible to modulation by various mechanisms. In this paper we compare the differences in properties of these channels as deduced from studies on transfected cells and isolated cardiomyocytes and discuss the factors involved in modulation of channel properties. Next, we evaluate the consequences of alterations in expression and modulation of channel properties for cardiac function. Therefore, we have compared reports on genetically engineered animals and discuss this information in relation to various pathophysiological disorders.
van Veen
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Department of Medical Physiology, University Medical Center Utrecht, Utrecht, The Netherlands.
van Rijen
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HV
Opthof
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D000818:Animals; D002318:Cardiovascular Diseases / Q000378:metabolism*; D018031:Connexin 43 / Q000378:metabolism; D017630:Connexins / Q000378:metabolism; D017629:Gap Junctions / Q000378:metabolism*; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D008322:Mammals / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D023421:Models, Animal; D009206:Myocardium / Q000378:metabolism*; D000097003:Gap Junction alpha-5 Protein
D018031:Connexin 43; D017630:Connexins; D007473:Ion Channels; D000097003:Gap Junction alpha-5 Protein; C082920:connexin 45