title: Special dyeing, histochemistry, immunohistochemistry and ultrastructure: A study of mast cells/eosinophilic granules cells (MCs/EGC) from Centropomus parallelus intestine.
abstract: Intestine mast cells/eosinophilic granule cells (MCs/EGC) of the marine species Centropomus parallelus (fat snook) were first studied using light and electron microscopy techniques. Mast cells are cells from the connective tissue found in almost all organs and tissues of vertebrates. In fish, they appear in greater numbers in parts of their bodies that are exposed to their environment, such as skin, gills and intestine. The granules in fat snook's mast cell contain a variety of substances, such as histamine, heparin, chondroitin sulfate, serotonin, proteases and cytokines. The present study of intestine MCs/EGC was carried out in 20 specimens of fat snook. Samples of tissue were fixed in Bouin solution and in buffered formalin. Ferric hematoxylin - Congo red, pH6 acridine orange, pH2.5 and pH0,5 Alcian Blue (AB), toluidine blue, PAS, AB + PAS and immunohistochemistry protocols were used. In the mucosa and submucosa layers, MCs/EGCs granules with basic contents were evidenced by Congo red staining, and with acid contents granules were identified through pH 2.5 and 0,5 AB, and acridine orange. Basic and acid contents were simultaneously evidenced using ferric hematoxylin - Congo red stain. Metachromasia was observed in both mucosal and submucosal mast cells. Neutral glycoproteins were evidenced by using PAS protocol, glycosaminoglycan through AB and both simultaneously through AB + PAS. In immunohistochemistry assays, MCs/EGC were positive for tryptase, chymase and serotonin. As in mammals, the study of samples fixed in modified Karnovsky for transmission electron microscopy evidenced that most of the MCs granules were spherical and showed varying electron density, as described in previous reports on other teleost fish species. The metachromasia observed and the identification of tryptase, chymase and serotonin suggest a great similarity between fat snook's MCs/EGC and those described in the mucosa of mammals.
authors.affiliation: Department of Morphology and Genetics, Laboratory of Histology and Structural Biology, Federal University of São Paulo, São Paulo, SP, Brazil; Morphology Department, Adventist University Center of São Paulo, São Paulo, SP, Brazil. Electronic address: wemesonf@hotmail.com.
authors.forename: Wémeson F
authors.initials: WF
authors.lastname: da Silva
authors.affiliation: Department of Morphology and Genetics, Laboratory of Histology and Structural Biology, Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Manuel J
authors.initials: MJ
authors.lastname: Simões
authors.affiliation: Department of Morphology and Genetics, Laboratory of Histology and Structural Biology, Federal University of São Paulo, São Paulo, SP, Brazil; Department of Neurology and Neurosurgery, Laboratory of Neurophysiology and Exercise Physiology, Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Robson C
authors.initials: RC
authors.lastname: Gutierre
authors.affiliation: Department of Morphology and Genetics, Laboratory of Histology and Structural Biology, Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Mizue I
authors.initials: MI
authors.lastname: Egami
authors.affiliation: Morphology Department, Adventist University Center of São Paulo, São Paulo, SP, Brazil.
authors.forename: Antenor A
authors.initials: AA
authors.lastname: Santos
authors.affiliation: Laboratory of Cell Biology, Butantan Institute, São Paulo, SP, Brazil.
authors.forename: Marta M
authors.initials: MM
authors.lastname: Antoniazzi
authors.affiliation: Department of Morphology and Genetics, Laboratory of Histology and Structural Biology, Federal University of São Paulo, São Paulo, SP, Brazil.
authors.forename: Gisela R
authors.initials: GR
authors.lastname: Sasso
authors.affiliation: Fishery Institute, São Paulo, SP, Brazil.
authors.forename: Maria José T
authors.initials: MJT
authors.lastname: Ranzani-Paiva
mesh_terms: D000818:Animals; D004804:Eosinophils / Q000166:cytology* / Q000648:ultrastructure; D007150:Immunohistochemistry / Q000662:veterinary; D007422:Intestines / Q000166:cytology / Q000648:ultrastructure; D008407:Mast Cells / Q000166:cytology* / Q000648:ultrastructure; D046529:Microscopy, Electron, Transmission / Q000662:veterinary; D010473:Perciformes / Q000276:immunology*; D013194:Staining and Labeling / Q000662:veterinary
keywords: Centropomus parallelus; Histochemistry; Immunohistochemistry; Mast cells; Ultrastructure