Figure 6.

The effect of chlorpromazine on F-actin in rat kidney slices: rat kidney slices were treated with and without CPZ 400 µM 15 and 60 min (A) before fixation and immunostaining with anti-AQP2 antibody (red). F-actin was labeled with FITC-conjugated phalloidin (green). The basal condition (NT) showed apical or cytoplasmic distribution of AQP2 and F-actin in principal cells from the outer medulla. F-actin was also observed in the basolateral membrane. In contrast, CPZ treatment at both 15 and 60 min resulted in basolateral accumulation of AQP2 (arrows). F-actin appears more abundant in the apical pole than the basolateral pole in outer medullary principal cells. A comparison of F-actin distribution between the untreated condition and the 60 min CPZ treatment (inserts) shows a marked modification of F-actin distribution that favors apical membrane localization over basolateral localization (see quantification in B and C). The images are representative of three independent experiments (bar = 10 µm for all panels). Fluorescence intensity of F-actin at the apical and basolateral membranes was analyzed and expressed as the % of the total F-actin fluorescence in the cell (panels B and C). More than 20 cells were analyzed in 3 different animals and results were expressed as an average of each experiment (panel B; means ± SD, n = 3). They were analyzed using the Student t test (***p < 0.001 and *p < 0.05). In panel C, all of the individual measurements from the three stained tissues are illustrated together to show the spread in values among the conditions tested.