中文摘要：

很少研究探索了的背景过渡 cardiomyocytes.This 学习的里面的钠水流( INa )动力学试图探索过渡 cardiomyocytes 类型和 .Methods 的动力学整个房间的补丁夹钳技术被用来在兔子 hearts.Results 的 Koch 三角学习孤立的过渡 cardiomyocytes 的快速的 INa 最大的振幅和密度在类型的 INa 一种and 类型是(-1627?敤楲敶?牦浯琠敨瀠牥灩敨慲???慷?獡慳敹?祢洠硩摥氠略潫祣整爠慥瑣潩??剌?整瑳?慌瑣瑡?敤票牤

英文摘要：

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 α and β. 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. Results Maximal amplitude and density of INa in type a and type β was （-1627±288） pA （α）, （-35.17±6.56） pA/pF （β） and （-3845±467） pA （α）, （-65.64±10.23） pA/pF （β） （P 〈0.05）. Steady state activation curves of INa, fitted to a Boltzmann distribution for both types, were sigmoid in shape. Half activation voltage and slope factors did not significantly differ between types at （-43.46±0.85） mV （α）, （-41.39±0.47） mV （β） or （9.04±0.66） mV （α）, （11.08±0.89） mV （β）. Steady state inactivation curves of INa, fitted to a Boltzmann distribution in both types were inverse ＂S＂ shape. Half inactivation voltage and slope factors were （-109.9±0.62） mV （α）, （-107.5±0.49） mV （β） and （11.78±0.36） mV （α）, （11.57±0.27） mV （β）, （P〉0.05）, but time constants of inactivation were significantly different at （1.10±0.19） mV （α） and （2.37±0.33） ms （β）, （P 〈0.05）. Time constants of recovery from inactivation of INa for both types were （122.16±27.43） mV （α） and （103.84±2.8.97） ms （β） （P 〈0.05）. Conclusions Transitional cardiomyocytes in rabbit hearts show a heterogeneous, voltage gated and time dependent fast inward sodium current. Types α and β show the features of INa similar to those in slow- and fast-response myocytes, with probably better automaticity and conductivity, respectively.