Boyd C A, Vatish M
Department of Human Anatomy, University of Oxford, UK.
Jpn J Physiol. 1994;44 Suppl 2:S273-80.
Conductive chloride transport in the brush border of the human placental epithelium has been determined by measurement of radioactive chloride flux (influx and efflux) and anion diffusion potentials. This conductance is inhibited specifically by low micromolar concentrations of arachidonic acid whereas the K+ permeability of this membrane is increased by arachidonic acid. The conductive pathway for anions is inhibited by 9-AC and has the permeability sequence SCN > I > NO3 > Br > Cl > F > gluconate; it is also permeant to HCO3-. Functionally the control of these anion and cationic conductances by arachidonic acid will be important in regulating epithelial transport and nutrient delivery to the fetus since they will set the value of the resting potential across the apical surface of the syncytiotrophoblast.
通过测量放射性氯通量（流入和流出）以及阴离子扩散电位，已确定人胎盘上皮刷状缘中的氯传导情况。这种电导受到低微摩尔浓度花生四烯酸的特异性抑制，而该膜的钾离子通透性则因花生四烯酸而增加。阴离子的传导途径受到9-AC抑制，其通透性顺序为SCN＞I＞NO3＞Br＞Cl＞F＞葡萄糖酸盐；它对HCO3-也具有通透性。从功能上讲，花生四烯酸对这些阴离子和阳离子电导的控制在调节上皮运输和向胎儿的营养输送方面将很重要，因为它们将设定合体滋养层顶端表面静息电位的值。
