title: Immunocytochemical localization of platelet-type arachidonate 12-lipoxygenase in mouse blood cells.
abstract: Arachidonate 12-lipoxygenase is an enzyme that oxygenates the 12 position of arachidonic acid to produce its 12-hydroperoxy derivative. We were interested in the tissue distribution and subcellular localization of the platelet-type 12-lipoxygenase, which is distinguished from the leukocyte type by several criteria. Antiserum was raised in rabbits against purified recombinant arachidonate 12-lipoxygenase of human platelets. When mouse bone marrow cells and lung were immunostained and observed by light and electron microscopy, the positively stained cells were platelets, megakaryocytes, and eosinophils. 12-Lipoxygenase was localized in the cytoplasm of platelets but was hardly detectable in the plasma membrane and intracellular organelles. The enzyme was found in the cytoplasm of immature megakaryocytes with kidney-shaped nuclei and a few profiles of demarcation membranes, as well as in the mature form with well-developed demarcation membranes. These results indicated the expression of 12-lipoxygenase at an early stage in the course of megakaryocytopoiesis.
authors.affiliation: Department of Biochemistry, Tokushima University School of Medicine, Japan.
authors.forename: M
authors.initials: M
authors.lastname: Nakamura
authors.forename: N
authors.initials: N
authors.lastname: Ueda
authors.forename: K
authors.initials: K
authors.lastname: Kishimoto
authors.forename: T
authors.initials: T
authors.lastname: Yoshimoto
authors.forename: S
authors.initials: S
authors.lastname: Yamamoto
authors.forename: K
authors.initials: K
authors.lastname: Ishimura
mesh_terms: D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; D000818:Animals; D000906:Antibodies; D001092:Arachidonate 12-Lipoxygenase / Q000032:analysis / Q000097:blood*; D001792:Blood Platelets / Q000201:enzymology* / Q000648:ultrastructure; D001854:Bone Marrow Cells; D002851:Chromatography, High Pressure Liquid; D004804:Eosinophils / Q000201:enzymology* / Q000648:ultrastructure; D006412:Hematopoietic Stem Cells / Q000201:enzymology* / Q000648:ultrastructure; D006801:Humans; D006893:Hydroxyeicosatetraenoic Acids / Q000032:analysis / Q000097:blood; D007150:Immunohistochemistry / Q000379:methods; D008041:Linoleic Acids / Q000032:analysis / Q000097:blood; D008168:Lung / Q000166:cytology / Q000201:enzymology; D008533:Megakaryocytes / Q000201:enzymology* / Q000648:ultrastructure; D051379:Mice; D016253:Microscopy, Immunoelectron / Q000379:methods; D011994:Recombinant Proteins / Q000032:analysis
chemical_list: D000906:Antibodies; D006893:Hydroxyeicosatetraenoic Acids; D008041:Linoleic Acids; D011994:Recombinant Proteins; C024348:13-hydroxy-9,11-octadecadienoic acid; D019377:12-Hydroxy-5,8,10,14-eicosatetraenoic Acid; C025984:15-hydroxy-5,8,11,13-eicosatetraenoic acid; D001092:Arachidonate 12-Lipoxygenase