title: Prostaglandin transporter in the rat brain: its localization and induction by lipopolysaccharide.
abstract: Prostaglandin E2 (PGE2) is produced in the brain during infectious/inflammatory diseases, and it mediates acute-phase responses including fever. In the recovery phase of such diseases, PGE2 disappears from the brain through yet unidentified mechanisms. Rat prostaglandin transporter (PGT), which facilitates transmembrane transport of PGE2, might be involved in the clearance of PGE2 from the brain. Here, we examined the cellular localization of PGT mRNA and its protein in the brains of untreated rats and those injected intraperitoneally with a pyrogen lipopolysaccharide (LPS) or saline. PGT mRNA was weakly expressed in the arachnoid membrane of untreated rats and saline-injected ones, but was induced in blood vessels of the subarachnoidal space and choroid plexus and in arachnoid membrane at 5 h and 12 h after LPS injection. In the same type of cells, PGT-like immunoreactivity was found in the cytosol and cell membrane even under nonstimulated conditions, and its level was also elevated after LPS injection. PGT-positive cells in blood vessels were identified as endothelial cells. In most cases, PGT was not colocalized with cyclooxygenase-2, a marker of prostaglandin-producing cells. The PGE2 level in the cerebrospinal fluid reached its peak at 3 h after LPS, and then dropped over 50% by 5 h, which time point coincides with the maximum PGT mRNA expression and enhanced level of PGT protein. These results suggest that PGT is involved in the clearance of PGE2 from the brain during the recovery phase of LPS-induced acute-phase responses.
authors.affiliation: Faculty of Education; Shiga University ; Otsu, Shiga, Japan.
authors.forename: Rika
authors.initials: R
authors.lastname: Hosotani
authors.affiliation: Department of Physiology and Pharmacology; Robarts Research Institute; Schulich School of Medicine & Dentistry; University of Western Ontario ; London, ON, Canada.
authors.forename: Wataru
authors.initials: W
authors.lastname: Inoue
authors.affiliation: Medical Research Institute; Tokyo Women's Medical University ; Shinjuku, Tokyo, Japan.
authors.forename: Takako
authors.initials: T
authors.lastname: Takemiya
authors.affiliation: Neural Plasticity Project; Tokyo Metropolitan Institute of Medical Science ; Setagaya-ku, Tokyo, Japan.
authors.forename: Kanato
authors.initials: K
authors.lastname: Yamagata
authors.affiliation: Department of Intelligence Science and Technology; Graduate School of Informatics; Kyoto University ; Sakyo-ku, Kyoto, Japan.
authors.forename: Shigeo
authors.initials: S
authors.lastname: Kobayashi
authors.affiliation: Faculty of Biomedical Engineering; Osaka Institute of Technology ; Asahi-ku, Osaka, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Matsumura
keywords: arachnoids; cytokines; endothelial cells; fever; organic anion transporter