Action of ANP on the nongenomic dose-dependent biphasic effect of aldosterone on NHE1 in proximal S3 segment

► Aldosterone stimulated/impaired the Na+/H+ exchanger in S3 segments. ► The intracellular pH recovery rate and cytosolic free calcium concentration were investigated by using the fluorescent probes BCECF-AM and FLUO-4-AM. ► The nongenomicaldosterone effects on NHE1 are affected by ANP, RU 486 and BAPTA. ► The intracellular Ca2+ regulates the NHE1 activity.