title: Effects of exposure to 1-bromopropane on astrocytes and oligodendrocytes in rat brain.
abstract: OBJECTIVE
  Human cases of 1-bromopropane (1-BP) toxicity showed ataxic gait and cognitive dysfunction, whereas rat studies showed pyknotic shrinkage in cerebellar Purkinje cells and electrophysiological changes in the hippocampus. The present study investigated the effects of 1-BP on astrocytes and oligodendrocytes in the rat cerebellum and hippocampus to find sensitive markers of central nervous system toxicity.
  
  
  METHODS
  Forty-eight F344 rats were divided into four equal groups and exposed to 1-BP at 0, 400, 800 and 1,000 ppm for 8 h/day; 7 days/week, for 4 weeks. Nine and three rats per group were used for biochemical and histopathological studies, respectively.
  
  
  RESULTS
  Kluver-Barrera staining showed pyknotic shrinkage in the cytoplasm of Purkinje cells and nuclei of granular cells in the cerebellum at 1,000 ppm. Immunohistochemical analysis showed increased length of glial fibrillary acidic protein (GFAP)-positive processes of astrocytes in the cerebellum, hippocampus and dentate gyrus at 800 and 1,000 ppm. The myelin basic protein (MBP) level was lower at 1,000 ppm. The numbers of astrocytes and granular cells per tissue volume increased at 400 ppm or higher.
  
  
  CONCLUSIONS
  The present study showed that elongation of processes of astrocytes accompanies degeneration of granular cells and Purkinje cells in the cerebellum of the rats exposed to 1-BP. The decrease in MBP and number of oligodendrocytes suggest adverse effects on myelination. The increase in astrocyte population per tissue volume in the cerebellum might be a sensitive marker of 1-BP neurotoxicity, but the underlying mechanism for this change remains elusive.
authors.affiliation: Department of Occupational and Environmental Health, Nagoya University Graduate School of Medicine, Nagoya University, Japan.
authors.forename: Sahabudeen Sheik
authors.initials: SS
authors.lastname: Mohideen
authors.forename: Sahoko
authors.initials: S
authors.lastname: Ichihara
authors.forename: Kaviarasan
authors.initials: K
authors.lastname: Subramanian
authors.forename: Zhenlie
authors.initials: Z
authors.lastname: Huang
authors.forename: Hisao
authors.initials: H
authors.lastname: Naito
authors.forename: Junzoh
authors.initials: J
authors.lastname: Kitoh
authors.forename: Gaku
authors.initials: G
authors.lastname: Ichihara
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000187:drug effects*; D002531:Cerebellum / Q000187:drug effects*; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D006624:Hippocampus / Q000187:drug effects*; D006842:Hydrocarbons, Brominated / Q000633:toxicity; D008297:Male; D004676:Myelin Basic Protein / Q000187:drug effects; D009836:Oligodendroglia / Q000187:drug effects*; D011689:Purkinje Cells / Q000187:drug effects; D012333:RNA, Messenger; D051381:Rats; D011916:Rats, Inbred F344
chemical_list: D006842:Hydrocarbons, Brominated; D004676:Myelin Basic Protein; D012333:RNA, Messenger; C118559:1-bromopropane