Choroid plexus epithelial cells in adult rats show structural alteration but not apoptosis following an exposure to hypobaric hypoxia

The choroid plexus in adult rats was examined for any structural alteration or apoptotic cell death following a high altitude exposure which leads to the development of hypobaric hypoxia due to reduced oxygen tension in the a tmospheric air. Caspase-3 (a protease which mediates apoptosis) immunoreact ivity was absent in the choroid plexus epithelial cells in the control rats and following altitude exposure; Bcl-2 (anti-apoptotic protein) and Bax (p ro-apoptotic protein) immunoreactivity were upregulated at 3 h-2 days follo wing the altitude exposure when compared to the controls but not in longer surviving rats. At the ultrastructural level, glycogen particles and vacuol es were observed in some epithelial cells at 7 days following the altitude exposure. It is suggested that transient exposure to high altitude may not cause much damage to the choroid plexus epithelial cells except for some st ructural alteration which may be due to altered metabolism of the cells in response to hypobaric hypoxia. (C) 2001 Elsevier Science Ireland Ltd. All r ights reserved.