title: Cytochemical, immunocytochemical and ultrastructural observations on leukocytes and thrombocytes of fat snook (Centropomus parallelus).
abstract: The cytochemical, immunocytochemical and ultrastructural characteristics of leukocytes and thrombocytes in the peripheral blood of the fat snook (Centropomus paralellus) - a fish occurring in Brazil - were investigated. The cytochemical methods were performed to demonstrate four enzymatic reactions - o-toluidine-hydrogen peroxide, naphtol AS-MX phosphate, naphtol AS-BI phosphate and alpha-naphtil acetate to detect myeloperoxidase (MPO), alkaline phosphatase (ALP), acid phosphatase (ACP) and non-specific esterase (α-NAE), respectively - and two non-enzymatic ones - Periodic-Acid Schiff (PAS) and Sudan black B (SBB) to detect the occurrence of glycogen and phospholipids, respectively. Immunocytochemical method utilizing polyclonal rabbit antibody against mammal metalloproteinases (MMPs) 2 and 9 were done. Standard method for Electron Microscopy (EM) was applied for the ultrastructural study. The cytochemical reactions were positive in neutrophils for MPO, ACP, α-NAE, glycogen and phospholipids; in lymphocytes for ACP and α-NAE; in monocytes for ACP and α-NAE and in thrombocytes for ACP, α-NAE and glycogen. Only neutrophils were positive for MMPs 2 and 9, and none of the cells studied were positive for ALP. Ultrastructurally: 1) neutrophil showed a spherical shape with a spherical, indented or lobulated euchromatic nucleus, and cytoplasm containing granules of varied sizes and mitochondria of varied shapes and sizes. The nucleus/cytoplasm relation and the size of granules suggest neutrophil maturation in peripheral blood; 2) lymphocytes showed partially heterochromatic nucleus and minimal cytoplasm; 3) monocytes had long cytoplasmic projections, an indented nucleus, evident nucleolus and cytoplasm with granules of varied sizes and vacuoles; 4) thrombocytes were predominantly elliptical or roughly spherical in shape, had a partially heterochromatic nucleus and cytoplasm containing electron-dense granules, intricate canalicular system and vacuoles occasionally holding phagocytic material.
authors.affiliation: Morphology Department, Histology Division and Coordinator of Comparative Hematology Laboratory, UNIFESP-EPM, SP, Brazil. wemesonf@hotmail.com
authors.forename: Wémeson F
authors.initials: WF
authors.lastname: da Silva
authors.forename: Mizue I
authors.initials: MI
authors.lastname: Egami
authors.forename: Antenor A
authors.initials: AA
authors.lastname: Santos
authors.forename: Marta M
authors.initials: MM
authors.lastname: Antoniazzi
authors.forename: Marcelo
authors.initials: M
authors.lastname: Silva
authors.forename: Robson C
authors.initials: RC
authors.lastname: Gutierre
authors.forename: Maria José R
authors.initials: MJ
authors.lastname: Paiva
mesh_terms: D000818:Animals; D001792:Blood Platelets / Q000737:chemistry / Q000166:cytology* / Q000276:immunology / Q000648:ultrastructure; D001938:Brazil; D004950:Esterases / Q000097:blood; D006003:Glycogen / Q000097:blood; D007150:Immunohistochemistry / Q000662:veterinary; D007962:Leukocytes / Q000737:chemistry / Q000166:cytology* / Q000276:immunology / Q000648:ultrastructure; D020778:Matrix Metalloproteinase 2 / Q000097:blood; D020780:Matrix Metalloproteinase 9 / Q000097:blood; D008854:Microscopy, Electron / Q000662:veterinary; D010473:Perciformes / Q000276:immunology; D009195:Peroxidase / Q000097:blood; D010743:Phospholipids / Q000097:blood
chemical_list: D010743:Phospholipids; D006003:Glycogen; D009195:Peroxidase; D004950:Esterases; D020778:Matrix Metalloproteinase 2; D020780:Matrix Metalloproteinase 9