Graf J, Gautam A, Boyer J L
Proc Natl Acad Sci U S A. 1984 Oct;81(20):6516-20. doi: 10.1073/pnas.81.20.6516.
Hepatocyte couplets were isolated by collagenase perfusion from rat liver. Between adjacent cells, the bile canaliculus forms a closed space into which secretion occurs. As in intact liver, Mg2+-ATPase is localized at the canalicular lumen, the organic anion fluorescein is excreted, and secretion is modified by osmotic gradients. By passing a microelectrode through one cell into the canalicular vacuole, a transepithelial potential profile was obtained. In 27 cell couplets the steady-state intracellular (-26.3 +/- 5.3 mV) and intracanalicular (-5.9 +/- 3.3 mV) potentials were recorded at 37 degrees C with reference to the external medium. Input resistances were determined within the cell (86 +/- 23 M omega) and in the bile canalicular lumen (32 +/- 17 M omega) by passing current pulses through the microelectrode. These data define electrical driving forces for ion transport across the sinusoidal, canalicular, and paracellular barriers and indicate ion permeation across a leaky paracellular junctional pathway. These findings indicate that the isolated hepatocyte couplet is an effective model for electrophysiologic studies of bile secretory function.
通过胶原酶灌注从大鼠肝脏分离出肝细胞对。相邻细胞之间，胆小管形成一个封闭的空间，分泌物排入其中。与完整肝脏一样，Mg2 + -ATP酶定位于胆小管腔，有机阴离子荧光素被排泄，并且分泌受到渗透梯度的调节。通过将微电极穿过一个细胞进入胆小管泡，获得了跨上皮电位分布。在27个肝细胞对中，在37℃下相对于外部介质记录稳态细胞内（-26.3±5.3 mV）和胆小管内（-5.9±3.3 mV）电位。通过使电流脉冲通过微电极来测定细胞内（86±23 MΩ）和胆小管腔内（32±17 MΩ）的输入电阻。这些数据定义了跨窦状、胆小管和细胞旁屏障的离子转运的电驱动力，并表明离子通过渗漏的细胞旁连接途径渗透。这些发现表明，分离的肝细胞对是胆汁分泌功能电生理研究的有效模型。
