Fig. 3.

PGE2 activates AQP2 without an elevation in cAMP in mpkCCD cells. a PGE2-induced AQP2 phosphorylation at S269. PGE2 (10 nM) was added to the basolateral side of the mpkCCD cells for 1 h, as previously described [31]. b PGE2-induced AQP2 trafficking. mpkCCD cells were treated with PGE2 (10 nM) for 1 h, and the subcellular localization of AQP2 was then analyzed by immunofluorescence and confocal microscopy. The larger panels display confocal sections of the apical regions of the cells. Z-stack confocal images are shown at the top of each panel. Representative confocal images of three independent experiments are shown. Scale bars, 10 µm. c No significant elevation of cAMP concentration in response to PGE2. The mpkCCD cells were treated with PGE2 (10 nM) or [deamino-Cys1, d-Arg8]-vasopressin (dDAVP) (1 nM) for 1 h. Bars are mean values ± SD of three experiments. Asterisks indicate a significant difference as compared with the control. **p < 0.01