Regional prostaglandin levels in cerebral ischaemia.

: Regional quantitative studies of brain prostaglandins (PG) in gerbils with bilateral carotid ligation have shown increases in PG2α in all areas of ischaemia but with no increases in PGE2. Pretreatment of animals with indomethacin (3 mg/kg) reduced this response, whereas dexamethasone (2.5 mg/kg) had no such effect. PGE1 and thromboxane-B2 were found not to be present in our preparation. The significance of these findings lies in the fact that both drugs, which are known to inhibit the development of ischaemic oedema, have now been shown to produce markedly different effects on prostaglandin levels. This may indicate either, that prostaglandins are not involved in is chaemic oedema formation, or, that the drugs have different mechanisms of action.