Regulation of conductive chloride transport in human placental brush border membrane vesicles.
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.
Boyd
C A
CA
Department of Human Anatomy, University of Oxford, UK.
Vatish
M
M
D016718:Arachidonic Acid / Q000494:pharmacology; D001639:Bicarbonates / Q000378:metabolism; D002712:Chlorides / Q000378:metabolism*; D006801:Humans; D017136:Ion Transport / Q000502:physiology*; D008564:Membrane Potentials / Q000187:drug effects; D008871:Microvilli / Q000502:physiology*; D010920:Placenta / Q000502:physiology*; D012964:Sodium
D001639:Bicarbonates; D002712:Chlorides; D016718:Arachidonic Acid; D012964:Sodium