title: Cell-cycle blockage associated with increased apoptotic cells in the thymus of chickens fed on diets high in fluorine.
abstract: Three hundred 1-day-old Avian broilers were divided into four groups and fed on control diet (fluorine 23 mg/kg) and high-fluorine (F) diets (400 mg/kg, high-F group I; 800 mg/kg, high-F group II; 1200 mg/kg, high-F group III) for 42 days (n = 75/group). The growth index (GI) was obviously decreased in the three high-F groups, which indicated the inhibited development of thymus. Histopathologically, the population of thymocytes was decreased in the thymic lobule in the three high-F groups. As measured by flow cytometry, thymocytes in G(0)/G(1) phase were significantly increased while thymocytes in S phase, G(2) + M phase and proliferating index (PI) value were obviously decreased in the three high-F groups. Also, the percentage of apoptotic thymocytes was greatly increased in the three high-F groups when compared with that of control group. At the same time, the occurrence frequencies of apoptotic thymocyte were markedly increased in the three high-F groups, with the appearance of dilated endoplasmic reticulum in high-F groups II and III ultra-structurally. The results showed that excess dietary F in the range of 400-1200 mg/kg caused histological lesions, G(0)/G(1) arrest and cellular apoptosis in the thymus, which inhibited the development of thymus and finally led to impaired cellular immune function.
authors.affiliation: Department of Veterinary Medicine, Sichuan Agricultural University, Ya'an, Sichuan, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Chen
authors.forename: Hengmin
authors.initials: H
authors.lastname: Cui
authors.forename: Yun
authors.initials: Y
authors.lastname: Cui
authors.forename: Caimin
authors.initials: C
authors.lastname: Bai
authors.forename: Tao
authors.initials: T
authors.lastname: Gong
authors.forename: Xi
authors.initials: X
authors.lastname: Peng
mesh_terms: D000284:Administration, Oral; D000821:Animal Feed; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002645:Chickens; D004247:DNA / Q000096:biosynthesis; D005434:Flow Cytometry / Q000379:methods; D017611:Fluorine Compounds / Q000633:toxicity*; D006128:Growth / Q000187:drug effects; D007399:Interphase / Q000187:drug effects* / Q000502:physiology; D011003:Ploidies; D013950:Thymus Gland / Q000187:drug effects* / Q000254:growth & development / Q000473:pathology
chemical_list: D017611:Fluorine Compounds; D004247:DNA