title: Macrophage activity and histopathology of the lymphohematopoietic organs in male Wistar rats orally exposed to single or mixed pesticides.
abstract: The noxious effects of low or effective dose exposure to single or mixed pesticides on macrophage activity and the lymphohematopoietic organs were investigated. Male Wistar rats were orally exposed to dichlorvos, dicofol, endosulfan, dieldrin and permethrin, either as single or combined mixtures during a 28-day study containing eight groups: one group received a semipurified diet (non-treated); two groups received a semipurified diet containing low dose mixture (dieldrin 0.025 mg/kg, endosulfan, 0.6 mg/kg, dicofol 0.22 mg/kg, dichlorvos 0.23 mg/kg, permethrin 5 mg/kg) or an effective dose mixture (dichlorvos 2.3 mg/kg, dicofol 2.5 mg/kg, endosulfan 2.9 mg/kg, dieldrin 0.05 mg/kg and permethrin 25.0 mg/kg), respectively; the other five groups received a semipurified diet containing each single pesticide in effective doses. At sacrifice, the thymus, spleen, mesenteric lymph nodes, Payer's patches and bone marrow were removed for histological analysis. Peritoneal macrophages were obtained to determine the phagocytosis and spreading indexes and tumoral necrosis factor alpha (TNF-α), nitric oxide (NO) and H₂O₂ production. Exposure to pesticide mixtures did not alter the percentage of macrophage phagocytosis and spreading, TNF-α production or the NO and H₂O₂ release when compared to the non-treated group. Neither was there any apparent evidence that a pesticide mixture at low or effective doses altered the histological structure of the lymphohematopoietic organs. The findings indicate that short-term treatment with pesticide mixtures did not induce an apparent immunotoxic effect in male Wistar rats.
authors.affiliation: a Department of Pathology, Botucatu Medical School , UNESP - Univ. Estadual Paulista , Botucatu , São Paulo State , Brazil.
authors.forename: Marcela Rodrigues
authors.initials: MR
authors.lastname: De Camargo
authors.forename: Luís Fernando
authors.initials: LF
authors.lastname: Barbisan
authors.forename: Meire França
authors.initials: MF
authors.lastname: Martinez
authors.forename: Carla Adriene
authors.initials: CA
authors.lastname: Da Silva Franchi
authors.forename: João Lauro Viana
authors.initials: JL
authors.lastname: De Camargo
authors.forename: Ana Lúcia Tozzi
authors.initials: AL
authors.lastname: Spinardi-Barbisan
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000187:drug effects* / Q000276:immunology; D002478:Cells, Cultured; D008198:Lymph Nodes / Q000187:drug effects / Q000276:immunology; D008221:Lymphoid Tissue / Q000187:drug effects* / Q000276:immunology; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects* / Q000276:immunology; D008297:Male; D010575:Pesticides / Q000633:toxicity*; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000187:drug effects / Q000276:immunology; D013950:Thymus Gland / Q000187:drug effects / Q000276:immunology; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
chemical_list: D010575:Pesticides; D014409:Tumor Necrosis Factor-alpha