Kinsey V E, Hightower K R
Invest Ophthalmol Vis Sci. 1978 Feb;17(2):186-90.
Active transport of sodium out of rabbit lenses was shown to be carrier mediated by observing the dependence of efflux of 22Na on intracellular concentration of nonlabeled sodium which previously was elevated by incubating lenses at 0 degree C. Velocity of sodium efflux increased asymptotically with increasing concentrations of intracellular sodium, demonstrating saturation of the carrier. The maximum velocity of the sodium pump based on Michaelis-Menten kinetics was found to be 4.6 mumol/hr/lens, and the half-saturation of the carrier, which appeared to involve a single site, occurred at 36 mM.
通过观察22Na外流对非标记钠细胞内浓度的依赖性，发现兔晶状体中钠的主动转运是由载体介导的，此前通过在0℃下孵育晶状体使非标记钠细胞内浓度升高。钠外流速度随着细胞内钠浓度的增加而渐近增加，表明载体饱和。基于米氏动力学，钠泵的最大速度为4.6 μmol/小时/晶状体，载体的半饱和（似乎涉及单个位点）发生在36 mM处。
