Fig. 1.
Effects of extracellular prostaglandin E2 (PGE2) on short-circuit current (Isc) in mouse inner medullary collecting duct (mIMCD)-K2 cells. A: representative trace shows the effect of apical and basal addition of PGE2 on Isc. A indicates amiloride (10−5 M) added to the apical bath. PGE2 (7.7 × 10−8 M) was added to the apical (a) and basal (b) side. Additions of cystic fibrosis transmembrane conductance regulator (CFTR) inhibitor-172 (CI-172) (10−5 M) and of flufenamic acid (FFA) (2 × 10−4 M) to the apical side are shown. B: representative Isc trace indicates the cumulative dose response to basal addition of PGE2. Increasing concentrations of PGE2 were added to the basal side, as indicated. C: cumulative dose-response curve derived from average sustained Isc increases (IscPGE2) after basal PGE2 addition. Values are means ± SE (n = 12 filters).