ATP-Sensitive Potassium Channel Currents in Eccentrically Hypertrophied Cardiac Myocytes of Volume-Overloaded Rats
ATP-sensitive potassium channels (KATP) protect the myocardium from hypertrophy induced by pressure-overloading. In this study, we determined the effects of these channels in volume-overloading. We compared the effects of a KATP agonist and a KATP antagonist on sarcolemmal transmembrane current dens...
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2011-01-01
|
| Series: | International Journal of Cell Biology |
| Online Access: | http://dx.doi.org/10.1155/2011/838951 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1832556169242083328 |
|---|---|
| author | Zikiar V. Alvin Richard M. Millis Wissam Hajj-Mousssa Georges E. Haddad |
| author_facet | Zikiar V. Alvin Richard M. Millis Wissam Hajj-Mousssa Georges E. Haddad |
| author_sort | Zikiar V. Alvin |
| collection | DOAJ |
| description | ATP-sensitive potassium channels (KATP) protect the myocardium from hypertrophy induced by pressure-overloading. In this study, we determined the effects of these channels in volume-overloading. We compared the effects of a KATP agonist and a KATP antagonist on sarcolemmal transmembrane current density (pA/pF) clamped at 20 mV increments of membrane potential from −80 to +40 mV in ventricular cardiac myocytes. The basal outward potassium pA/pF in myocytes of volume-overloaded animals was significantly smaller than that in the myocytes of sham-operated controls. Treatment of the control myocytes with the KATP agonist cromakalim increased pA/pF significantly. This increase was blocked by the KATP antagonist glibenclamide. Treatment of the hypertrophied myocytes from volume-overloaded animals with cromakalim and in the presence and absence of glibenclamide did not change pA/pF significantly. These findings suggest that eccentrically hypertrophied cardiac myocytes from volume-overloading may be unresponsive to specific activation/inactivation of KATP and that dysfunctional KATP may fail to protect the myocardium from left ventricular hypertrophy associated with volume-overloading. |
| format | Article |
| id | doaj-art-f84229c3185a4839ad43a0d9ce2c3773 |
| institution | Kabale University |
| issn | 1687-8876 1687-8884 |
| language | English |
| publishDate | 2011-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | International Journal of Cell Biology |
| spelling | doaj-art-f84229c3185a4839ad43a0d9ce2c37732025-02-03T05:46:14ZengWileyInternational Journal of Cell Biology1687-88761687-88842011-01-01201110.1155/2011/838951838951ATP-Sensitive Potassium Channel Currents in Eccentrically Hypertrophied Cardiac Myocytes of Volume-Overloaded RatsZikiar V. Alvin0Richard M. Millis1Wissam Hajj-Mousssa2Georges E. Haddad3Department of Physiology & Biophysics, College of Medicine, Howard University, Washington, DC 20059, USADepartment of Physiology & Biophysics, College of Medicine, Howard University, Washington, DC 20059, USADepartment of Physiology & Biophysics, College of Medicine, Howard University, Washington, DC 20059, USADepartment of Physiology & Biophysics, College of Medicine, Howard University, Washington, DC 20059, USAATP-sensitive potassium channels (KATP) protect the myocardium from hypertrophy induced by pressure-overloading. In this study, we determined the effects of these channels in volume-overloading. We compared the effects of a KATP agonist and a KATP antagonist on sarcolemmal transmembrane current density (pA/pF) clamped at 20 mV increments of membrane potential from −80 to +40 mV in ventricular cardiac myocytes. The basal outward potassium pA/pF in myocytes of volume-overloaded animals was significantly smaller than that in the myocytes of sham-operated controls. Treatment of the control myocytes with the KATP agonist cromakalim increased pA/pF significantly. This increase was blocked by the KATP antagonist glibenclamide. Treatment of the hypertrophied myocytes from volume-overloaded animals with cromakalim and in the presence and absence of glibenclamide did not change pA/pF significantly. These findings suggest that eccentrically hypertrophied cardiac myocytes from volume-overloading may be unresponsive to specific activation/inactivation of KATP and that dysfunctional KATP may fail to protect the myocardium from left ventricular hypertrophy associated with volume-overloading.http://dx.doi.org/10.1155/2011/838951 |
| spellingShingle | Zikiar V. Alvin Richard M. Millis Wissam Hajj-Mousssa Georges E. Haddad ATP-Sensitive Potassium Channel Currents in Eccentrically Hypertrophied Cardiac Myocytes of Volume-Overloaded Rats International Journal of Cell Biology |
| title | ATP-Sensitive Potassium Channel Currents in Eccentrically Hypertrophied Cardiac Myocytes of Volume-Overloaded Rats |
| title_full | ATP-Sensitive Potassium Channel Currents in Eccentrically Hypertrophied Cardiac Myocytes of Volume-Overloaded Rats |
| title_fullStr | ATP-Sensitive Potassium Channel Currents in Eccentrically Hypertrophied Cardiac Myocytes of Volume-Overloaded Rats |
| title_full_unstemmed | ATP-Sensitive Potassium Channel Currents in Eccentrically Hypertrophied Cardiac Myocytes of Volume-Overloaded Rats |
| title_short | ATP-Sensitive Potassium Channel Currents in Eccentrically Hypertrophied Cardiac Myocytes of Volume-Overloaded Rats |
| title_sort | atp sensitive potassium channel currents in eccentrically hypertrophied cardiac myocytes of volume overloaded rats |
| url | http://dx.doi.org/10.1155/2011/838951 |
| work_keys_str_mv | AT zikiarvalvin atpsensitivepotassiumchannelcurrentsineccentricallyhypertrophiedcardiacmyocytesofvolumeoverloadedrats AT richardmmillis atpsensitivepotassiumchannelcurrentsineccentricallyhypertrophiedcardiacmyocytesofvolumeoverloadedrats AT wissamhajjmousssa atpsensitivepotassiumchannelcurrentsineccentricallyhypertrophiedcardiacmyocytesofvolumeoverloadedrats AT georgesehaddad atpsensitivepotassiumchannelcurrentsineccentricallyhypertrophiedcardiacmyocytesofvolumeoverloadedrats |