AJP - Heart Watch the video to learn how APS reaches out to developing nations.
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

Am J Physiol Heart Circ Physiol 279: H35-H46, 2000;
0363-6135/00 $5.00
This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Web of Science (49)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Xiao, Y.-F.
Right arrow Articles by Leaf, A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Xiao, Y.-F.
Right arrow Articles by Leaf, A.
Vol. 279, Issue 1, H35-H46, July 2000

Coexpression with beta 1-subunit modifies the kinetics and fatty acid block of hH1alpha Na+ channels

Yong-Fu Xiao1,2,4, Sterling N. Wright5, Ging Kuo Wang3,4, James P. Morgan1,4, and Alexander Leaf2,4

1 Charles A. Dana Research Institute and Harvard-Thorndike Laboratory, Cardiovascular Division, Department of Medicine, Beth Israel Deaconess Medical Center, 2 Department of Medicine, Massachusetts General Hospital, and 3 Department of Anesthesia, Brigham and Women's Hospital, 4 Harvard Medical School, Boston, Massachusetts 02215; and 5 Department of Biological Sciences, Murray State University, Murray, Kentucky 42071

Voltage-gated cardiac Na+ channels are composed of alpha - and beta 1-subunits. In this study beta 1-subunit was cotransfected with the alpha -subunit of the human cardiac Na+ channel (hH1alpha ) in human embryonic kidney (HEK293t) cells. The effects of this coexpression on the kinetics and fatty acid-induced suppression of Na+ currents were assessed. Current density was significantly greater in HEK293t cells coexpressing alpha - and beta 1-subunits (INa,alpha beta ) than in HEK293t cells expressing alpha -subunit alone (INa,alpha ). Compared with INa,alpha , the voltage-dependent inactivation and activation of INa,alpha beta were significantly shifted in the depolarizing direction. In addition, coexpression with beta 1-subunit prolonged the duration of recovery from inactivation. Eicosapentaenoic acid [EPA, C20:5(n-3)] significantly reduced INa,alpha beta in a concentration-dependent manner and at 5 µM shifted the midpoint voltage of the steady-state inactivation by -22 ± 1 mV. EPA also significantly accelerated channel transition from the resting state to the inactivated state and prolonged the recovery time from inactivation. Docosahexaenoic acid [C22:6(n-3)], alpha -linolenic acid [C18:3(n-3)], and conjugated linoleic acid [C18:2(n-6)] at 5 µM significantly inhibited both INa,alpha beta and INa,alpha . In contrast, saturated and monounsaturated fatty acids had no effects on INa,alpha beta . This finding differs from the results for INa,alpha , which was significantly inhibited by both saturated and unsaturated fatty acids. Our data demonstrate that functional association of beta 1-subunit with hH1alpha modifies the kinetics and fatty acid block of the Na+ channel.

alpha -subunit; cardiac sodium ion channel; polyunsaturated fatty acids


This article has been cited by other articles:


Home page
 Am. J. Physiol. Cell Physiol.Home page
Y.-F. Xiao, E. M. TenBroek, J. J. Wilhelm, P. A. Iaizzo, and D. C. Sigg
Electrophysiological characterization of murine HL-5 atrial cardiomyocytes
Am J Physiol Cell Physiol, September 1, 2006; 291(3): C407 - C416.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Cell Physiol.Home page
Y.-F. Xiao, L. Ma, S.-Y. Wang, M. E. Josephson, G. K. Wang, J. P. Morgan, and A. Leaf
Potent block of inactivation-deficient Na+ channels by n-3 polyunsaturated fatty acids
Am J Physiol Cell Physiol, February 1, 2006; 290(2): C362 - C370.
[Abstract] [Full Text] [PDF]

Home page
 J. Thorac. Cardiovasc. Surg.Home page
J.-Y. Min, Y. Yang, M. F. Sullivan, Q. Ke, K. L. Converso, Y. Chen, J. P. Morgan, and Y.-F. Xiao
Long-term improvement of cardiac function in rats after infarction by transplantation of embryonic stem cells
J. Thorac. Cardiovasc. Surg., February 1, 2003; 125(2): 361 - 369.
[Abstract] [Full Text] [PDF]

Home page
 Am. J. Physiol. Heart Circ. Physiol.Home page
D. P. Goel, T. G. Maddaford, and G. N. Pierce
Effects of omega -3 polyunsaturated fatty acids on cardiac sarcolemmal Na+/H+ exchange
Am J Physiol Heart Circ Physiol, October 1, 2002; 283 (4): H1688 - H1694.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
Y. Yang, J.-Y. Min, J. S. Rana, Q. Ke, J. Cai, Y. Chen, J. P. Morgan, and Y.-F. Xiao
VEGF enhances functional improvement of postinfarcted hearts by transplantation of ESC-differentiated cells
J Appl Physiol, September 1, 2002; 93(3): 1140 - 1151.
[Abstract] [Full Text] [PDF]

Home page
 J. Appl. Physiol.Home page
J.-Y. Min, Y. Yang, K. L. Converso, L. Liu, Q. Huang, J. P. Morgan, and Y.-F. Xiao
Transplantation of embryonic stem cells improves cardiac function in postinfarcted rats
J Appl Physiol, January 1, 2002; 92(1): 288 - 296.
[Abstract] [Full Text] [PDF]

Home page
 Eur Heart JHome page
C Antzelevitch
The Brugada syndrome: diagnostic criteria and cellular mechanisms
Eur. Heart J., March 1, 2001; 22(5): 356 - 363.
[PDF]


HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Visit Other APS Journals Online