Fig. 4. Transmission electron micrographs illustrating OPN immunostaining in the descending thin limb from control (A), dehydrated (B), and hydrated (C) rats. OPN immunoreactivity increased in the Golgi apparatus and secretory vesicles in dehydrated animals. In contrast, after hydration, the labeling intensity declined to less than the controls. Note that the intercellular spaces between the thin epithelial cells were remarkably widened (asterisk) in hydrated rats. Scale bar = 2 µm.
