Bovine Neutrophil Functions and Periparturient Disorders

Cai, Tian Quan

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Description

Title

Bovine Neutrophil Functions and Periparturient Disorders

Author(s)

Cai, Tian Quan

Issue Date

1992

Doctoral Committee Chair(s)

Wagner, William C.

Department of Study

Veterinary Medical Science

Discipline

Veterinary Medical Science

Degree Granting Institution

University of Illinois at Urbana-Champaign

Degree Name

Ph.D.

Degree Level

Dissertation

Keyword(s)

• Biology, Animal Physiology
• Biology, Veterinary Science

Abstract

Neutrophil functions in periparturient normal cows (n = 46), and their relationship with the occurrence of retained placenta and metritis complex (RPM, n = 20), metritis (n = 18) and mastitis (n = 13), were studied by collecting blood samples via jugular vein twice weekly from 1 week before to 4 weeks after parturition. Seasonal variation of neutrophil function assays (n = 4 ovariectomized cows) and modulation of neutrophil functions in normal and abnormal postpartum cows (RPM, metritis or mastitis, n = 5 per group) were investigated in vitro by using arachidonic acid metabolites ($\rm PGE\sb2:$ 10$\sp{-6}$ M, PGF$\sb{2\alpha}:$ 10$\sp{-7}$ M, LTB$\sb4:$ 10$\sp{-8}$ M, and lipoxin B: 10$\sp{-8}$ M), and recombinant human colony-stimulating factors (rhG-CSF: 1000 and 6000 units/ml, and rhGM-CSF: 5 and 15 ng/ml). The results of these experiments suggest the following conclusions: (1) Random migration and ingestion activity of neutrophils increased, but ADCC and myeloperoxidase activity decreased, which may increase susceptibility to infections; (2) Neutrophils, monocytes and eosinophils decreased after calving; (3) There were seasonal variations in bovine neutrophil functional assays; (4) Neutrophil functions were impaired in abnormal cows after calving. A prepartum defect was noticed in term of superoxide production (metritis) or chemotaxis (mastitis), suggesting the defect of neutrophil function as a predisposing factor in the occurrence of these disorders; (5) Neutrophils decreased after parturition in cows with RPM or metritis, but not with mastitis. Immature neutrophils increased in cows with RPM or mastitis, but not with metritis; (6) In vitro treatment of neutrophils with AA metabolites and rhCSFs did not affect functions of neutrophils from either normal or abnormal postpartum cows; (7) Incubation of neutrophils in a 37$\sp\circ$C water bath for 30 minutes might restore the functions of neutrophils from cows with RPM or metritis, and further impair the functions of neutrophils from cows with mastitis.

Graduation Semester

1992

Type of Resource

text

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