EFFECT OF CHRONIC REM-SLEEP DEPRIVATION ON PITUITARY, HYPOTHALAMUS AND HIPPOCAMPUS PGE(2) AND PGD(2) BIOSYNTHESIS IN THE MOUSE

Given the often reported relationships between sleep-wake regulation a nd the cerebral prostaglandins (PGs), the effect of chronic rapid eye movement (REM) sleep deprivation on brain PGE(2) and PGD(2) biosynthes is in mouse was evaluated, since they are known to have opposite actio ns as respectively wake- and sleep-inducing substances. Mice were subj ected to 5 and 10 days of REM sleep deprivation by the flower pot tech nique. After sacrifice, PGE(2) and PGD(2) were determined in the pitui tary, hypothalamus and hippocampus. Except in the pituitary where no c hanges were shown, the PGE(2)/PGD(2) ratio was significantly enhanced after 5 and 10 days of REM sleep loss, when compared to control. These results showed an alteration of cerebral PGE(2) and PGD(2) biosynthes is, resulting in a shift from PGD(2) toward PGE(2). These results were not consistent with a role of PGD(2) as a sleep-promoting substance a s, if that was the case, it would be increased during the REM sleep de privation. But they do not rule out its involvement as a facilitating substance.