EFFECTS OF ISCHEMIA ON PROSTAGLANDIN-H SYNTHASE-2 EXPRESSION IN PIGLET CHOROID-PLEXUS

We examined effects of ischemia on expression of prostaglandin H synth ase-l (PGHS-1) and prostaglandin H synthase-e (PGHS-2) in piglet choro id plexus. Ten minutes of ischemia was induced by increasing intracran ial pressure. Whole choroid plexus was removed and fixed and/or frozen after 1, 2, 4, and 8 h of recovery from anoxic stress. In addition, t issues were obtained from untreated animals or from time control anima ls. Tissues were analyzed for mRNA, using RNase protection assays, and for proteins, using immunohistochemical approaches. Limited, but dete ctable PGHS-2 immunoreactivity was present in choroid plexus under nor mal conditions, and there was no difference between time-control and n on-treated animals. Further, PGHS-2 mRNA increased by 2-4 h after isch emia, and enhanced immunoreactivity for PGHS-2 was present at 8 h afte r ischemia. Enhanced immunoreactivity for PGHS-2 was present in vascul ar endothelial cells as well as cuboidal epithelial cells and macropha ges. In contrast, PGHS-1 mRNA did not increase following ischemia. We conclude that PGHS-2 is present in piglet choroid plexus under normal conditions and that ischemia increases levels of PGHS-2 in choroid ple xus.