TY - JOUR
T1 - Reduced swelling-activated Cl- current densities in hypertrophied ventricular myocytes of rabbits with heart failure
AU - van Borren, Marcel M. G. J.
AU - Verkerk, Arie O.
AU - Vanharanta, Sakari K.
AU - Baartscheer, Antonius
AU - Coronel, Ruben
AU - Ravesloot, Jan H.
PY - 2002
Y1 - 2002
N2 - Objective: Hypertrophied myocytes of failing hearts have prolonged action potential durations. It is unknown how the swelling-activated Cl- current affects the abnormal AP configuration. Methods: We studied (I-Cl,I-swell) in ventricular myocytes isolated from failing and age-matched normal rabbit hearts. We applied whole-cell patch-clamp methodology and activated I-Cl,I-swell by lowering tonicity of the superfusate. Results: Neither with ruptured-patch nor with amphotericin B perforated-patch, whole-cell clamp we found I-Cl,I-swell active under isotonic conditions in either the normal or the hypertrophied failing heart (HFH) myocytes. caused AP shortening and resting membrane potential (V-m) depolarization in an osmotic gradient-dependent fashion. However, in the HFH myocytes swelling-induced AP changes were significantly smaller, even though the cells underwent the same relative change in planar cell surface area. Voltage-clamp experiments revealed that in HFH myocytes I-Cl,I-swell current density was similar to50% reduced. Conclusion: Reduced I-Cl,I-swell densities in HFH myocytes cause limited AP shortening and V-m depolarization upon swelling of the cells. (C) 2002 Elsevier Science BY. All rights reserved
AB - Objective: Hypertrophied myocytes of failing hearts have prolonged action potential durations. It is unknown how the swelling-activated Cl- current affects the abnormal AP configuration. Methods: We studied (I-Cl,I-swell) in ventricular myocytes isolated from failing and age-matched normal rabbit hearts. We applied whole-cell patch-clamp methodology and activated I-Cl,I-swell by lowering tonicity of the superfusate. Results: Neither with ruptured-patch nor with amphotericin B perforated-patch, whole-cell clamp we found I-Cl,I-swell active under isotonic conditions in either the normal or the hypertrophied failing heart (HFH) myocytes. caused AP shortening and resting membrane potential (V-m) depolarization in an osmotic gradient-dependent fashion. However, in the HFH myocytes swelling-induced AP changes were significantly smaller, even though the cells underwent the same relative change in planar cell surface area. Voltage-clamp experiments revealed that in HFH myocytes I-Cl,I-swell current density was similar to50% reduced. Conclusion: Reduced I-Cl,I-swell densities in HFH myocytes cause limited AP shortening and V-m depolarization upon swelling of the cells. (C) 2002 Elsevier Science BY. All rights reserved
U2 - https://doi.org/10.1016/S0008-6363(01)00507-7
DO - https://doi.org/10.1016/S0008-6363(01)00507-7
M3 - Article
C2 - 11922897
SN - 0008-6363
VL - 53
SP - 869
EP - 878
JO - Cardiovascular research
JF - Cardiovascular research
IS - 4
ER -