%0 Journal Article %1 Cote_2000_2051 %A C�t�, K. %A Proteau, S. %A Teijeira, J. %A Rousseau, E. %D 2000 %J J. Mol. Cell. Cardiol. %K 11040108 Aged, Animals, Atria, Bilayers, Blotting, Calcium Calcium, Cardiac, Channel Channel, Channels, Child, Comparative Conductivity, Dogs, Elapid Electric Female, Gating, Gov't, Heart Humans, Ion Isoforms, Lipid Magnesium, Male, Middle Muscle Myocytes, Non-U.S. Potassium Potassium, Protein Proteins, Rabbits, Receptor Red, Release Research Reticulum, Ruthenium Ryanodine Ryanodine, Sarcoplasmic Sheep, Species Specificity, Study, Support, Transport, Venoms, Western, %N 11 %P 2051--2063 %R 10.1006/jmcc.2000.1236 %T Characterization of the sarcoplasmic reticulum K$^+$ and Ca$^2+$-release channel-ryanodine receptor-in human atrial cells. %U http://dx.doi.org/10.1006/jmcc.2000.1236 %V 32 %X Since the role of sarcoplasmic reticulum (SR) in the E-C coupling of mammalian atrial cells has long been a subject of debate, biochemical, electrophysiological and immunological assays were performed in order to define and compare the properties of the Ca$^2+$-release channel-ryanodine receptor (RyR)-from atrial and ventricular tissues. Cardiac SR preparations from human, canine and ovine tissues were compared using (3)Hryanodine binding, channel reconstitution into planar lipid bilayers and Western blot analysis involving RyR antibodies. (3)Hryanodine binding assays revealed a K(d)value of; 2.5 n M for all investigated cardiac tissues. Bound (3)Hryanodine was Ca$^2+$-dependent with similar EC(50)values of 0.43, 0.49 and 0.79 microM for human atrium, canine ventricle and ovine atrium, respectively. However the density of binding sites was 4.5 times lower in atrial than in ventricular tissues. Beyond the presence of selective K$^+$channels (gamma=188 pS) recorded in the SR enriched fraction of human atrium, the activity of a large conducting (gamma=671 pS) cationic channel was also observed. The latter displayed typical characteristics of Ca$^2+$-release channels which were activated by 10 microM free Ca$^2+$ and 2 m M ATP. Western blot analysis revealed the presence of the RyR2 isoform in atrial and ventricular samples whereas no immunoreactivity was detected with specific RyR1 and RyR3 antibodies. Our results, obtained at the molecular level, are consistent with the presence of functional SR in human atrial cells. The human atrial Ca$^2+$-release channel displays binding and regulating properties typical of the RyR2 isoform.

@article{Cote_2000_2051, abstract = {Since the role of sarcoplasmic reticulum (SR) in the E-C coupling of mammalian atrial cells has long been a subject of debate, biochemical, electrophysiological and immunological assays were performed in order to define and compare the properties of the {C}a$^{2+}$-release channel-ryanodine receptor (RyR)-from atrial and ventricular tissues. Cardiac SR preparations from human, canine and ovine tissues were compared using [(3)H]ryanodine binding, channel reconstitution into planar lipid bilayers and Western blot analysis involving RyR antibodies. [(3)H]ryanodine binding assays revealed a K(d)value of; 2.5 n M for all investigated cardiac tissues. Bound [(3)H]ryanodine was {C}a$^{2+}$-dependent with similar EC(50)values of 0.43, 0.49 and 0.79 microM for human atrium, canine ventricle and ovine atrium, respectively. However the density of binding sites was 4.5 times lower in atrial than in ventricular tissues. Beyond the presence of selective {K}$^{+}$channels (gamma=188 pS) recorded in the SR enriched fraction of human atrium, the activity of a large conducting (gamma=671 pS) cationic channel was also observed. The latter displayed typical characteristics of {C}a$^{2+}$-release channels which were activated by 10 microM free [{C}a$^{2+}$] and 2 m M ATP. Western blot analysis revealed the presence of the RyR2 isoform in atrial and ventricular samples whereas no immunoreactivity was detected with specific RyR1 and RyR3 antibodies. Our results, obtained at the molecular level, are consistent with the presence of functional SR in human atrial cells. The human atrial {C}a$^{2+}$-release channel displays binding and regulating properties typical of the RyR2 isoform.}, added-at = {2009-06-03T11:20:58.000+0200}, author = {C�t�, K. and Proteau, S. and Teijeira, J. and Rousseau, E.}, biburl = {https://www.bibsonomy.org/bibtex/2e9b82ebf1f7702678374d0903dd24a12/hake}, description = {The whole bibliography file I use.}, doi = {10.1006/jmcc.2000.1236}, file = {Cote_2000_2051.pdf:Cote_2000_2051.pdf:PDF}, interhash = {0d7b3b59ad4bb240f05b18f91ccd744b}, intrahash = {e9b82ebf1f7702678374d0903dd24a12}, journal = {J. Mol. Cell. Cardiol.}, key = 187, keywords = {11040108 Aged, Animals, Atria, Bilayers, Blotting, Calcium Calcium, Cardiac, Channel Channel, Channels, Child, Comparative Conductivity, Dogs, Elapid Electric Female, Gating, Gov't, Heart Humans, Ion Isoforms, Lipid Magnesium, Male, Middle Muscle Myocytes, Non-U.S. Potassium Potassium, Protein Proteins, Rabbits, Receptor Red, Release Research Reticulum, Ruthenium Ryanodine Ryanodine, Sarcoplasmic Sheep, Species Specificity, Study, Support, Transport, Venoms, Western,}, month = Nov, number = 11, pages = {2051--2063}, pii = {S0022282800912367}, pmid = {11040108}, timestamp = {2009-06-03T11:21:09.000+0200}, title = {Characterization of the sarcoplasmic reticulum K$^+$ and {C}a$^{2+}$-release channel-ryanodine receptor-in human atrial cells.}, url = {http://dx.doi.org/10.1006/jmcc.2000.1236}, volume = 32, year = 2000 }