Selenate efflux from human placental brush border membrane vesicles was studied using an ion-exchange column assay. Selenate efflux was found to be mediated almost exclusively by a temperature dependent DIDS-sensitive pathway. Chromate markedly inhibited selenate efflux: in contrast medium selenate had no effect. It is concluded that selenate and sulphate share a common pathway for transport across the human placental microvillus membrane.
Abbreviations DIDS, 4-acetamido-4′-isothiocyanostilbene-2-2′-disulphonate