Reverse mode of the sodium/calcium exchanger subtype 3 in interstitial cells of Cajal from rat bladder.

Objective To investigate how the sodium/calcium exchanger subtype 3 (NCX3) and its reverse mode contribute to the function of interstitial cells of Cajal (ICCs) from the rat bladder. Methods The study used 20 female Wistar rats. We observed the expression of the NCX3 expression in the bladder using reverse transcriptase-polymerase chain reaction and Western blotting. The NCX3 in ICCs was also confirmed by double-labeled fluorescence. NCX3 functions in reverse mode of ICCs were observed using confocal microscopy with preload fluo-3AM, and its currents were evaluated using the whole-cell patch clamp technique, with or without the NCX3 inhibitor KB-R7943 (5 and 30μM), with an afterward identification of ICCs using single-cell polymerase chain reaction. Results NCX3 was confirmed in rat bladder ICCs. The time required for the intracellular calcium concentration [Ca 2+ ] i of NCX3 was enhanced by KB-R7943 (5μM, P  ≤.01). Moreover, KB-R7943 (5 and 30μM) significantly decreased the currents generated by the reverse mode of NCX3 from the ICCs ( P Conclusion NCX3 is expressed in rat bladder ICCs. The reverse mode of NCX3 can generate [Ca 2+ ] i of the bladder ICCs.