Salicylate inhibits human placental sulphate transport in vitro

The effect of salicylate on sulphate transport by the human placenta has been studied using isolated brush-border membrane vesicles and placental tissue slices. Sulphate uptake by isolated vesicles was inhibited in a dose dependent fashion (K1 approximately 3 mM) by salicylate. It appears that this drug blocks sulphate accumulation in a non-competitive manner. Sulphate efflux from preloaded vesicles was also found to be markedly reduced by salicylate in a non-competitive fashion. Consistent with the vesicle studies salicylate inhibited sulphate transport by placental tissue slices. The results suggest that salicylate ingestion could compromise feto-placental sulphate homeostasis. In addition we have found that the aspirin-like drug, flufenamic acid, inhibits sulphate transport by isolated microvillus membrane vesicles.