Vargas F F
J Gen Physiol. 1968 Jan;51(1):13-27. doi: 10.1085/jgp.51.1.13.
The hydraulic conductivity of the membranes surrounding the giant axon of the squid, Dosidicus gigas, was measured. In some axons the axoplasm was partially removed by suction. Perfusion was then established by insertion of a second pipette. In other axons the axoplasm was left intact and only one pipette was inserted. In both groups hydrostatic pressure was applied by means of a water column in a capillary manometer. Displacement of the meniscus in time gave the rate of fluid flowing across the axon sheath. In both groups osmotic differences across the membrane were established by the addition of a test molecule to the external medium which was seawater. The hydraulic conductivity determined by application of hydrostatic pressure was 10.6 +/- 0.8.10(-8) cm/sec cm H(2)O in perfused axons and 3.2 +/- 0.6.10(-8) cm/sec cm H(2)O in intact axons. When the driving force was an osmotic pressure gradient the conductivity was 4.5 +/- 0.6 x 10(-10) cm/sec cm H(2)O and 4.8 +/- 0.9 x 10(-10) cm/sec cm H(2)O in perfused and intact axons, respectively. A comparable result was found when the internal solution was made hyperosmotic. The fluid flow was a linear function of the hydrostatic pressure up to 70 cm of water. Glycerol outflux and membrane conductance were increased 1.6 and 1.1 times by the application of hydrostatic pressure. These increments do not give an explanation of the difference between the filtration coefficients. Other possible explanations are suggested and discussed.
对太平洋褶柔鱼巨大轴突周围膜的水力传导率进行了测量。在一些轴突中，通过抽吸部分去除轴浆。然后通过插入第二个移液管建立灌注。在其他轴突中，轴浆保持完整，仅插入一个移液管。在两组中，均通过毛细管压力计中的水柱施加静水压力。弯月面随时间的位移给出了流体流过轴突鞘的速率。在两组中，通过向作为海水的外部介质中添加测试分子来建立跨膜的渗透差异。通过施加静水压力测定的灌注轴突的水力传导率为10.6±0.8×10⁻⁸ cm/sec cm H₂O，完整轴突的水力传导率为3.2±0.6×10⁻⁸ cm/sec cm H₂O。当驱动力为渗透压梯度时，灌注轴突和完整轴突的传导率分别为4.5±0.6×10⁻¹⁰ cm/sec cm H₂O和4.8±0.9×10⁻¹⁰ cm/sec cm H₂O。当内部溶液变为高渗时，得到了类似的结果。流体流量是高达70厘米水柱静水压力的线性函数。施加静水压力使甘油外流和膜电导分别增加了1.6倍和1.1倍。这些增加并不能解释过滤系数之间的差异。提出并讨论了其他可能的解释。
