Peters R
EMBO J. 1984 Aug;3(8):1831-6. doi: 10.1002/j.1460-2075.1984.tb02055.x.
Fluorescence microphotolysis was used to measure nucleocytoplasmic flux in single rat hepatocytes for a series of dextrans ranging in molecular mass from 3 to 150 kd. The cytoplasmic translational diffusion coefficient DC and the nucleoplasmic diffusion coefficient DN of a 62-kd dextran were also determined. DC was approximately 2 X 10(-8) and DN approximately 3 X 10(-8) cm2/s, i.e., 1/20-1/15 of the value in free solution. The mobile fraction amounted to 0.7-0.8 in measurements of both intracellular diffusion and nucleo-cytoplasmic flux. The flux of dextrans from cytoplasm to nucleus depended inversely on molecular mass with an exclusion limit between 17 and 41 kd suggesting that the nuclear envelope has functions of a molecular sieve. Employing the Pappenheimer-Renkin equations, a functional pore radius of 50-56 A was derived. By comparison with recent measurements on isolated liver cell nuclei, large quantitative differences between the intracellularly located and the isolated nucleus were revealed.
采用荧光显微光解技术，对一系列分子量在3至150kd之间的葡聚糖，测定了单个大鼠肝细胞中的核质通量。还测定了一种62kd葡聚糖的细胞质平移扩散系数DC和核质扩散系数DN。DC约为2×10(-8)，DN约为3×10(-8)cm2/s，即自由溶液中该值的1/20 - 1/15。在细胞内扩散和核质通量的测量中，可移动部分占0.7 - 0.8。葡聚糖从细胞质到细胞核的通量与分子量成反比，排除极限在17至41kd之间，这表明核膜具有分子筛的功能。利用帕彭海默-伦金方程，得出功能孔半径为50 - 56埃。与最近对分离的肝细胞核的测量结果相比，揭示了细胞内定位的细胞核与分离的细胞核之间存在很大的定量差异。
