TY - JOUR

T1 - KCNQ channels are involved in the regulatory volume decrease response in primary neonatal rat cardiomyocytes.

AU - Calloe, Kirstine

AU - Nielsen, Morten Schak

AU - Grunnet, Morten

AU - Schmitt, Nicole

AU - Jorgensen, Nanna Koschmieder

N1 - Keywords: Actins; Animals; Animals, Newborn; Anthracenes; Arrhythmias, Cardiac; Cell Adhesion; Cell Size; Cells, Cultured; Cytochalasin D; Electric Conductivity; Ion Transport; KCNQ Potassium Channels; Membrane Potentials; Myocardium; Myocytes, Cardiac; Rats; Rats, Wistar; Reperfusion Injury; Stress Fibers

PY - 2007

Y1 - 2007

N2 - Cardiomyocytes may experience significant cell swelling during ischemia and reperfusion. Such changes in cardiomyocyte volume have been shown to affect the electrical properties of the heart, possibly leading to cardiac arrhythmia. In the present study the regulatory volume decrease (RVD) response of neonatal rat cardiomyocytes was studied in intact single cells attached to coverslips, i.e. with an intact cytoskeleton. The potential contribution of KCNQ (Kv7) channels to the RVD response and the possible involvement of the F-actin cytoskeleton were investigated. The rate of RVD was significantly inhibited in the presence of the KCNQ channel blocker XE-991 (10 and 100 microM). Electrophysiological experiments confirmed the presence of an XE-991 sensitive current and Western blotting analysis revealed that KCNQ1 channel protein was present in the neonatal rat cardiomyocytes. Hypoosmotic cell swelling changes the structure of the F-actin cytoskeleton, leading to a more rounded cell shape, less pronounced F-actin stress fibers and patches of actin. In the presence of cytochalasin D (1 microM), a potent inhibitor of actin polymerization, the RVD response was strongly reduced, confirming a possible role for an intact F-actin cytoskeleton in linking cell swelling to activation of ion transport in neonatal rat cardiomyocytes. Udgivelsesdato: 2007-Jun

AB - Cardiomyocytes may experience significant cell swelling during ischemia and reperfusion. Such changes in cardiomyocyte volume have been shown to affect the electrical properties of the heart, possibly leading to cardiac arrhythmia. In the present study the regulatory volume decrease (RVD) response of neonatal rat cardiomyocytes was studied in intact single cells attached to coverslips, i.e. with an intact cytoskeleton. The potential contribution of KCNQ (Kv7) channels to the RVD response and the possible involvement of the F-actin cytoskeleton were investigated. The rate of RVD was significantly inhibited in the presence of the KCNQ channel blocker XE-991 (10 and 100 microM). Electrophysiological experiments confirmed the presence of an XE-991 sensitive current and Western blotting analysis revealed that KCNQ1 channel protein was present in the neonatal rat cardiomyocytes. Hypoosmotic cell swelling changes the structure of the F-actin cytoskeleton, leading to a more rounded cell shape, less pronounced F-actin stress fibers and patches of actin. In the presence of cytochalasin D (1 microM), a potent inhibitor of actin polymerization, the RVD response was strongly reduced, confirming a possible role for an intact F-actin cytoskeleton in linking cell swelling to activation of ion transport in neonatal rat cardiomyocytes. Udgivelsesdato: 2007-Jun

U2 - 10.1016/j.bbamcr.2007.02.008

DO - 10.1016/j.bbamcr.2007.02.008

M3 - Journal article

C2 - 17442416

VL - 1773

SP - 764

EP - 773

JO - B B A - General Subjects

JF - B B A - General Subjects

SN - 0304-4165

IS - 6

ER -