title: Heme oxygenase (HO) isoforms in experimental C6 glioma: an immunocytochemical study.
abstract: Abstract Because of their potential to regulate tumoural blood flow and interactions with nitric oxide the expression of the type 1 and 2 isoforms of heme oxygenase (HO-1 and HO-2) were evaluated in implanted C6 striatal gliomas. Immunocytochemistry using antibodies specific for HO-1 and HO-2 were used in 20 C6 glioma tumours. The bulk of the tumour parenchyma and endothelium was negative for both HO isoforms. Isolated, but weak staining for HO-1 was seen in most tumours with focally increased expression in perinecrotic regions. Cells morphologically resembling macrophages stained with both HO-1 and HO-2, but were not numerous. These findings suggest that carbon monoxide, unlike nitric oxide, does not have a major role in regulating tumoural blood flow in this experimental glioma model. These findings once again demonstrate the differences between human malignant glioma and experimental implantation glioma models.
authors.affiliation: Department of Clinical Neurosciences and Pathology, University of Edinburgh, Western General Hospital, UK.
authors.forename: S
authors.initials: S
authors.lastname: Lo
authors.forename: H S
authors.initials: HS
authors.lastname: Bell
authors.forename: S
authors.initials: S
authors.lastname: Yamaguchi
authors.forename: S B
authors.initials: SB
authors.lastname: Wharton
authors.forename: I R
authors.initials: IR
authors.lastname: Whittle
mesh_terms: D000818:Animals; D005910:Glioma / Q000098:blood supply / Q000201:enzymology* / Q000648:ultrastructure; D006419:Heme Oxygenase (Decyclizing) / Q000378:metabolism*; D051547:Heme Oxygenase-1; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D008565:Membrane Proteins; D009363:Neoplasm Proteins / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism; D051381:Rats; D014407:Tumor Cells, Cultured
chemical_list: D008565:Membrane Proteins; D009363:Neoplasm Proteins; D009569:Nitric Oxide; C496541:HMOX1 protein, human; D006419:Heme Oxygenase (Decyclizing); D051547:Heme Oxygenase-1