title: Toxicity to the hematopoietic and lymphoid organs of piglets treated with a therapeutic dose of florfenicol.
abstract: Florfenicol (FLO) is a broad-spectrum antibacterial agent for treatment of bacteriosis of piglets in veterinary practice. To study the toxicity to the hematopoietic and lymphoid organs of piglets treated with a therapeutic dose of FLO, 20 healthy weaned piglets were selected and randomly divided into two groups. Piglets in the FLO group were fed with fodder supplemented with 30mg/kg BW of FLO twice a day for 10 days. Blood samples were drawn at four time points: 1 day before FLO administration and 1, 7, and 14 days post-withdrawal. Three or four piglets were euthanized at each time point post-withdrawal and tissue samples (bone marrow, thymus and spleen) were collected for fixation and cryostorage. The levels of classical swine fever virus (CSFV) antibody against the vaccine, the concentrations of Hsp70 and IL-6 in serum and Hsp70 in tissues, and the mRNA expression levels of B-cell lymphoma 2 (bcl-2) and tumor suppressor p53 were detected, the hematology of the piglets were analyzed, and the histopathology and the status of apoptosis of the hematopoietic and lymphoid organs was examined. The results showed changes in several indicators in the FLO group 1 day post-withdrawal: the concentration of red blood cells (RBCs) was decreased, and that of platelets (PLTs) was significantly lower (p<0.05); the volumes of RBC and PLT were increased; the sum of blood lymphocytes was statistically decreased (p<0.05); the concentration of IL-6 was significantly increased (p<0.05); the concentrations of Hsp70 in serum and tissues were increased; obvious atrophy of the hematopoietic cell lines and partial replacement by fat cells were observed in bone marrow; thymus and spleen tissues showed lower concentrations and sparser arrangement of lymphocytes in the thymic medulla and white pulp of the spleen respectively; and the mRNA expression levels of bcl-2 in the three tissues were up-regulated, while that of p53 was down-regulated. With time after cessation of FLO administration, the indicators of the FLO group gradually returned to close to that of the control group and the histological lesions of the tissues gradually recovered, and the differences in the densities of lymphocytes and cell arrangements in the tissues between two groups gradually decreased. In conclusion, a therapeutic dose of FLO induces temporary toxicity in the hematopoietic and lymphoid organs of piglets to some extent, and influences hemopoiesis and immune function. These effects gradually decrease after cessation of FLO administration.
authors.affiliation: Animal Science and Technology Department of Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Dongfang
authors.initials: D
authors.lastname: Hu
authors.affiliation: Postdoctoral Workstation of DELISI Group, Weifang 262216, China.
authors.forename: Taixiang
authors.initials: T
authors.lastname: Zhang
authors.affiliation: Animal Science and Technology Department of Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Zhendong
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: Animal Science and Technology Department of Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Guangwen
authors.initials: G
authors.lastname: Wang
authors.affiliation: Animal Science and Technology Department of Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Fangkun
authors.initials: F
authors.lastname: Wang
authors.affiliation: Animal Science and Technology Department of Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Yajin
authors.initials: Y
authors.lastname: Qu
authors.affiliation: Animal Science and Technology Department of Shandong Agricultural University, Tai'an 271018, China.
authors.forename: Yujuan
authors.initials: Y
authors.lastname: Niu
authors.affiliation: Animal Science and Technology Department of Shandong Agricultural University, Tai'an 271018, China. Electronic address: liusid@sdau.edu.cn.
authors.forename: Sidang
authors.initials: S
authors.lastname: Liu
mesh_terms: D000818:Animals; D001772:Blood Cell Count / Q000662:veterinary; D001853:Bone Marrow / Q000276:immunology*; D018840:HSP70 Heat-Shock Proteins / Q000097:blood; D006651:Histocytochemistry / Q000662:veterinary; D020287:In Situ Nick-End Labeling / Q000662:veterinary; D015850:Interleukin-6 / Q000097:blood; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis; D012313:RNA / Q000737:chemistry / Q000235:genetics; D011897:Random Allocation; D060888:Real-Time Polymerase Chain Reaction / Q000662:veterinary; D013154:Spleen / Q000276:immunology*; D013552:Swine / Q000276:immunology*; D013839:Thiamphenicol / Q000008:administration & dosage / Q000009:adverse effects / Q000031:analogs & derivatives* / Q000494:pharmacology; D013950:Thymus Gland / Q000276:immunology*; D016159:Tumor Suppressor Protein p53 / Q000032:analysis
chemical_list: D018840:HSP70 Heat-Shock Proteins; D015850:Interleukin-6; D019253:Proto-Oncogene Proteins c-bcl-2; D016159:Tumor Suppressor Protein p53; D012313:RNA; C035534:florfenicol; D013839:Thiamphenicol
keywords: Anemia; Apoptosis; Bone marrow; Drug toxicity; Florfenicol; Immune organs