论文部分内容阅读
离子通道是一类跨膜糖蛋白,因有亲水性孔道,故可使带电荷的离子进行跨膜转运,进而产生和传导电信号。目前,心肌细胞膜上已发现Na~+、Ca~+2、K~+和Cl-4种离子通道,以Na~+通道的密度最大,在每个心肌细胞膜上的数量高达100万个,而Ca~+2通道仅2万个。心肌细胞膜Na~+通道的结构和特性与神经细胞或骨骼肌细胞膜上的Na~+通道明显不同。Na~+通道有除极心肌细胞,传导动作电位的作用,在整个动作电位时程中,Na~+通道有着三种不同状态,并循环转换。静息关闭(左图A):Na~+通道此时处于不活动的关闭状态,
Ion channel is a type of transmembrane glycoprotein, because of hydrophilic channels, it can make charged ions transmembrane transport, and then generate and conduct electrical signals. At present, Na ~ +, Ca ~ + 2, K ~ + and Cl-4 ion channels have been found on the membrane of cardiac muscle cells, and the density of Na ~ + channels is the largest in each membrane of myocardial cells up to 1 million Ca ~ + 2 channel only 20,000. The structure and properties of Na ~ + channel in cardiac myocyte membrane are distinctly different from Na ~ + channel in neuron or skeletal muscle cell membrane. Na ~ + channels have very cardiomyocytes, conduction action potential role in the entire action potential duration, Na ~ + channel has three different states, and cycle conversion. Resting off (left A): Na ~ + channel is inactive at this time off,