Response of epiplexus cells associated with the choroid plexus in the lateral ventricles of adult rats to high altitude exposure

The present study examined effects of high altitude exposure, which leads t o development of hypoxia, on epiplexus cells associated with the choroid pl exus in adult rats. At 2-5 h following exposure, epiplexus cells expressing inducible nitric oxide synthase (iNOS) were commonly observed. Increased e xpression of complement type 3 receptors (CR3) and major histocompatibility complex class II (MHC II) antigens was also observed 4-14 days after altit ude exposure. It is suggested that the early expression of iNOS in epiplexu s cells following an altitude exposure may protect the choroid plexus and v entricles from damage caused by reactive oxygen species during reoxygenatio n. The enhanced expression of CR3 receptors and MHC II antigens at later ti me intervals may be involved in protection of cerebral ventricular system f rom any infection that may accompany or follow altitude exposure. (C) 2000 Elsevier Science Ireland Ltd. All rights reserved.