Fig. 7.

Ultrastructural localization of AQP2 and caveolin-1. MDCK-hAQP2 cells were treated with forskolin for 30 min (a), and then washed and incubated without forskolin for 30 min (b). Ultrathin cryosections were double-labeled for AQP2 (12 nm colloidal gold) and caveolin-1 (6 nm colloidal gold). In forskolin-treated cells (a), some AQP2 is colocalized with caveolin-1 at caveolar structures in the apical membrane domain (arrows). AQP2 on the microvillous membrane is not colocalized with caveolin-1. When cells were washed and incubated without forskolin for 30 min (b), AQP2 was colocalized with caveolin-1 in the intracellular vesicles (arrows). Bars=100 nm.