title: Histopathology of the fish Corydoras paleatus contaminated with sublethal levels of organophosphorus in water and food.
abstract: The effects of contamination, through water or food, of a sublethal dose of the organophosphate methyl parathion were analyzed in tissues that are responsible for absorption (gills, intestine) and metabolism (liver), in the freshwater fish Corydoras paleatus. In gill respiratory lamellae, epithelial hyperplasia, edema, and detachment occurred, diminishing sooner after contamination by food than after contamination through water. In the intestine, lipoid vacuolization of enterocytes, apical cytoplasm, and an increase in goblet cell activity occurred mainly after ingestion of contaminated food. The liver exhibited cloudy swelling, bile stagnation, focal necrosis, atrophy, and vacuolization after contamination through both absorption routes, the highest degeneration being between T(8) and T(24). Metabolic processes that depend on liver function were equally impaired by the two routes of contamination, but secondary effects vary with gill and intestine pathologies as a consequence of water and food contamination, respectively. Therefore, a "safe" sublethal dose of methyl parathion causes serious health problems in C. paleatus.
authors.affiliation: Departamento de Biologia Celular, Universidade Federal do Paraná, Caixa Postal 19031, 81531-970, Curitiba, PR, Brazil. e.fanta@terra.com
authors.forename: Edith
authors.initials: E
authors.lastname: Fanta
authors.forename: Flávia Sant'Anna
authors.initials: FS
authors.lastname: Rios
authors.forename: Silvia
authors.initials: S
authors.lastname: Romão
authors.forename: Ana Cristina Casagrande
authors.initials: AC
authors.lastname: Vianna
authors.forename: Sandra
authors.initials: S
authors.lastname: Freiberger
mesh_terms: D000042:Absorption; D000818:Animals; D005399:Fishes / Q000502:physiology*; D005880:Gills / Q000473:pathology*; D007306:Insecticides / Q000009:adverse effects* / Q000493:pharmacokinetics; D008099:Liver / Q000473:pathology* / Q000502:physiology; D008743:Methyl Parathion / Q000009:adverse effects* / Q000493:pharmacokinetics; D014018:Tissue Distribution; D014874:Water Pollutants, Chemical / Q000009:adverse effects* / Q000493:pharmacokinetics
chemical_list: D007306:Insecticides; D014874:Water Pollutants, Chemical; D008743:Methyl Parathion