Pathological impact of hyperpolarization-activated chloride current peculiar to rat pulmonary vein cardiomyocytes

Electrophysiological Characteristics, Rhythm, Disturbances and Conduction Discontinuities Under Autonomic Stimulation in the Rat Pulmonary Vein Myocardium

“…C,D), which might be associated with an inhibition of I K1 current through stimulation of α 1 adrenergic receptors by NE . It should be also noted that both NE and ACh could affect chloride currents and thus modulate RP . In addition, though a role of Ca 2+ ‐activated K + (SK)‐channels in autonomic modulation of PV electrophysiology remains uncertain, it should be considered as well, especially in response to mechanical stress …”

“…25 It should be also noted that both NE and ACh could affect chloride currents and thus modulate RP. 26 In addition, though a role of Ca 2+ -activated K + (SK)-channels in autonomic modulation of PV electrophysiology remains uncertain, 27 it should be considered as well, especially in response to mechanical stress. 28 The results describing APD in PV and LA significantly vary between different studies and mainly rely on animal species used.…”

Comparative study of hyperpolarization-activated currents in pulmonary vein cardiomyocytes isolated from rat, guinea pig, and rabbit

“…The protocols used in this study were approved by the Animal Ethics Committee of the Akita University School of Medicine, Japan. Cell isolation procedures were essentially similar to those reported previously [10,11]. Male Wister rats (8-12 weeks old, 300-400 g) and male guinea pigs (5-10 weeks old, 400-700 g) were anesthetized by intraperitoneal injection of pentobarbital sodium (100 and 120 mg/kg for rats and guinea pigs, respectively).…”

“…Electrophysiological experiments demonstrated various types of spontaneous activity in PV cardiomyocytes in animal studies [4]. These include sinoatrial node-like spontaneous action potentials [5,6], digitalis-induced arrhythmia [7,8], noradrenalineinduced automaticity [9][10][11], stretch-induced automaticity [12] and pacing-induced spontaneous activity [6,13,14]. Such arrhythmogenic activity depends, in part, upon their distinct electrophysiological characteristics, i.e., the PV myocardium in general has a less negative resting membrane potential when compared with the atrial myocardium.…”

“…The I f is a mixed current of Na + and K + , and is characterized by its relatively slow time course of activation on hyperpolarization [15]. However, we previously found another I h which is carried by Cl − in rat PV cardiomyocytes [11]. We designated this current as the hyperpolarization-activated Cl − current (I Cl,h ).…”