ROLE OF CA-2+ AND PROSTAGLANDIN IN REGULATION OF ACTIVE NA+ TRANSPORT IN FROG-SKIN

1. 1. The role of prostaglandins and intracellular Ca2+ in regulation of active transepithelial sodium transport in frog skin were studied by examinations of effects of the calcium ionophore A23187 on short-circuit current (SCC) and intracellular voltage. 2. 2. A23187 and arachidonic acid induced a marked increase in both SCC and prostaglandin E2 synthesis. 3. 3. In indomethacin treated skins A23187 did not stimulate but on the contrary inhibited the basal SCC. 4. 4. The A23187-induced increase in SCC was associated with a decrease in the fractional resistance of the apical membrane and a depolarization of the cells. 5. 5. In skins pretreated with indomethacin, the A23187 induced inhibition of SCC coincided with a slight hyperpolarization of the cellular potential and an increase in fractional resistance of the apical membrane. © 1990.