title: Effect of oral exposure to fenitrothion and 3-methyl-4-nitrophenol on splenic cell populations and histopathological alterations in spleen in Wistar rats.
abstract: Fenitrothion (FNT) is used throughout the world as an insecticide in agriculture. To investigate the effect of FNT on the splenocytes and the underlying mechanism, FNT and its main metabolite, 3-methyl-4-nitrophenol (MNP), were administered orally to Wistar rats in daily doses of 0, 5 and 10 mg/kg, 4-5 days/week for 9 weeks. Splenocytes were harvested from control and exposed rats, and the following cell phenotypes were quantified by flow cytometry: (1) B cells (PE-CD45RA), (2) T cells (FITC-CD3), (3) T cell subsets (PE-CD4 and PerCPCD8), (4) natural killer (NK) cells (FITC-CD161a), (5) macrophages (FITC-CD11b), and (6) granulocyte (PE-granulocyte). Body weight, weight of the spleen, and histopathological alterations of spleens were also examined. The percentage of splenic CD8+ T cells and the ratio of CD8/CD4 in the group receiving 10 mg/kg FNT, and the percentages of splenic CD3+ and CD8+ T cells in the group receiving 10 mg/kg MNP were significantly decreased compared with those in the controls. FNT exposure also significantly decreased the weight of the spleen and body weight. In addition, apoptotic lymphocytes in spleen were observed in FNT-exposed rats under transmission electron microscope. However, FNT and MNP exposures did not affect splenic NK cells, B cells, macrophages, and granulocytes. The above findings indicate that FNT and MNP may selectively affect splenic T cells in rats.
authors.affiliation: Department of Hygiene and Public Health, Nippon Medical School, Bunkyo-ku, Tokyo, Japan. qing-li@nms.ac.jp
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.forename: Maiko
authors.initials: M
authors.lastname: Kobayashi
authors.forename: Hirofumi
authors.initials: H
authors.lastname: Inagaki
authors.forename: Yukiyo
authors.initials: Y
authors.lastname: Hirata
authors.forename: Shigeru
authors.initials: S
authors.lastname: Sato
authors.forename: Masamichi
authors.initials: M
authors.lastname: Ishizaki
authors.forename: Ai
authors.initials: A
authors.lastname: Okamura
authors.forename: Dong
authors.initials: D
authors.lastname: Wang
authors.forename: Tamie
authors.initials: T
authors.lastname: Nakajima
authors.forename: Michihiro
authors.initials: M
authors.lastname: Kamijima
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Kawada
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000187:drug effects / Q000473:pathology; D001835:Body Weight / Q000187:drug effects; D003408:Cresols / Q000633:toxicity*; D004785:Environmental Pollutants / Q000633:toxicity*; D005278:Fenitrothion / Q000633:toxicity*; D005434:Flow Cytometry; D006098:Granulocytes / Q000187:drug effects / Q000473:pathology; D007306:Insecticides / Q000633:toxicity*; D007694:Killer Cells, Natural / Q000187:drug effects / Q000473:pathology; D008264:Macrophages / Q000187:drug effects / Q000473:pathology; D008297:Male; D046529:Microscopy, Electron, Transmission; D009929:Organ Size / Q000187:drug effects; D051381:Rats; D017208:Rats, Wistar; D013154:Spleen / Q000187:drug effects* / Q000473:pathology / Q000648:ultrastructure; D013601:T-Lymphocytes / Q000187:drug effects / Q000473:pathology
chemical_list: D003408:Cresols; D004785:Environmental Pollutants; D007306:Insecticides; C008636:4-nitro-3-cresol; D005278:Fenitrothion