Postnatal changes in the localization of prostaglandin D synthetase from neurons to oligodendrocytes in the rat brain

Prostaglandin D synthetase (Urade, Y., Fujimoto, N., and Hayaishi, O. (1985) J. Biol. Chem. 260, 12410-12415) in the brain of 2- and 8-week-old rats was biochemically indistinguishable as judged by Mr (26,000), pI values (4.35-4.75), Km for prostaglandin H2 (approximately 20 microM), and requirement of sulfhydryl compounds. Furthermore, the enzyme was immunologically the same at both ages, as judged by immunotitration, Ouchterlony immunodiffusion, and immunoblotting analyses using a polyclonal and two monoclonal antibodies specific for the enzyme. However, the cellular localization of the enzyme was markedly different between the two ages, as examined by immunoperoxidase staining with the specific antibodies. The immunoreactivity was found in many neurons in 2-week-old rats but was not detected in most neurons in 8-week-old rats except for multipolar neurons in layers I-II of the neocortex and several clusters of dendrites in the pyriform cortex. In the adult rat, the immunoreactivity was mainly localized in oligodendrocytes. By immunoelectron microscopy, the immunoreactive deposits were seen in rough-surfaced endoplasmic reticulum and outer nuclear membrane of the glial cells.