Study Of Signal Transduction Pathways Regulating Ionic Channel Remodeling In Early Phase Of Cultured Rat Atrial Myocytes Induced By Rapid Pacing

Background and objectives:Atrial fibrillation is the most common tachyarrhythmia in clinical patients. Current treatment modalities for atrial fibrillation are far from satisfactory. The major causes and the underlying mechanisms of atrial fibrillation remain unclear. Recent studies have demonstrated that atrial electrical remodeling was an important contributing factor for the occurrence, persistence and maintenance of atrial fibrillation. The expression changes of ionic channels, especially L-type calcium channel and potassium channel Kv4.3, are the important molecular mechanism of atrial electrical remodeling. However, little information is available about the regulating mechanisms of ionic channels'expression during atrial fibrillation. This study was designed to establish a rapid paced cell model with primary cultured atrial myocytes. The regulating mechanisms of ionic channels'expression in the early phase induced by rapid pacing were investigated.Methods.1. The primary rat atrial myocyts were cultured, characteristics of the cultured myocytes was observed with light microscope and the cell phenotype was harvested by immunocytochemical stain to detectα-actin.2. The cellular model of rapid pacing was established with primary cultured atrial myocytes.3. The expressions of L-type calcium channelα1c and potassium channel Kv4.3 in cultured atrial myocytes were detected by immunocytochemistry, reverse transcription polymerase chain reaction(RT-PCR) and Western blot after rapid pacing.4. The intracellular free calcium concentration was detected by confocal microscopy under different conditions.