[Electrophysiologic characteristics of Ito in myocytes from cardiac Koch triangle].

Objective: To explore the electrophysiologic characteristics of Ito in myocytes from cardiac Koch triangle.

Methods: Patch clamp technique was employed to investigate the I-V and D-V relation, steady-state activation and inactivation kinetics of Ito from myocytes in Koch triangle of rabbit hearts.

Results: (1) The maximum peak current (pA) and peak current density (pA/pF) at +20 mV in PC (pacing cell), TC (transitonal cell) alpha,beta, AC (atrial cell) and PL (purkinje-like cell) cells were different from each other (P < 0.

Sodium current kinetics of transitional myocytes in Koch triangle of rabbit hearts.

Background: Few studies have explored the inward sodium current (INa) kinetics of transitional cardiomyocytes. This study aimed to explore the kinetics of transitional cardiomyocytes types alpha and beta.

Methods: The whole-cell patch clamp technique was used to study the rapid INa of isolated transitional cardiomyocytes in the Koch triangle of rabbit hearts.

Morphological and electrophysiological properties of single myocardial cells from Koch triangle of rabbit heart.

Background: The morphological and electrophysiological characteristics of cardiac cells in Koch triangle are still disputed. We studied the appearance and electrical properties of these diverse myocytes to elucidate their complex electrophysiological phenomena.

Methods: Experiments were conducted using cooled charge coupling device (CCD) system and whole cell, patch clamp technique to determine the morphology, action potential and sodium current density of single viable myocytes enzymatically isolated from the Koch triangle of rabbit hearts.

[Expression of L-type calcium channel alpha1C subunit in adult rat heart].

Objective: To investigate the expression and distribution of L-type calcium channel alpha1C subunits in adult rat heart.

Methods: HE staining was applied on the frozen sections of adult rat heart to identify the sinoatrial node (SAN), atrioventricular node (AVN), and posterior nodal extension (PNE). The protein expression of L-type calcium channel alpha1C in adult rat heart and its cellular localization were examined by Western blotting and immunohistochemistry, respectively.

Morphological and electrophysiological study on the inferior nodal extension and transitional cellular band in the rabbit atrioventricular junctional area.

Background: Advances in catheter ablation procedures for the treatment of supraventricular arrhythmias have created the need to understand better the morphological and electrophysiological characteristics of the inferior nodal extension (INE) and transitional cellular band (TCB) in the atrioventricular (AV) junctional area.

Methods: Firstly, we observed the histological features of 10 rabbit AV junctional areas by serial sections under light microscopy. Then we recorded the action potentials (APs) of transitional cells (TCs) in the INE, TCBs, AV node, and ordinary right atrial myocytes from the AV junctional area of 30 rabbits using standard intracellular microeletrode techniques.