title: Effect of endotoxic mastitis on epithelial cell numbers in the milk of dairy cows.
abstract: OBJECTIVE
  To measure epithelial cell percentages and somatic cell counts (SCCs) in milk and determine whether isoflupredone acetate reduces mammary gland epithelial cell sloughing in cows with acute endotoxin-induced mastitis.
  
  
  METHODS
  13 lactating Holstein cows.
  
  
  METHODS
  Determination of SCC and flow cytometric analysis of cytokeratin-positive (epithelial) cells in milk were performed before and 12 hours after induction of mastitis via intramammary administration of bacterial endotoxin in 8 cows and at the same time points in 5 cows without mastitis. Endotoxin-treated cows received isoflupredone acetate (20 mg) or saline (0.9% NaCl) solution (n = 4/group) IV after signs of mastitis developed.
  
  
  RESULTS
  At the 12-hour time point, mean +/- SD percentage of epithelial cells in milk increased from 2.74 +/- 1.93% to 42.11 +/- 36.21% and decreased from 5.73 +/- 4.52% to 5.31 +/- 1.93% in milk from cows with and without mastitis, respectively. Median (range) SCC in milk increased from 195,000 cells/mL (17,000 to 442,000 cells/mL) to 5,437,500 cells/mL (69,000 to 11,036,000 cells/mL) and from 19,000 cells/mL (9,000 to 125,000 cells/mL) to 51,000 cells/mL (10,000 to 835,000 cells/mL) in cows with and without mastitis, respectively. Changes in these variables were significantly greater in mastitis-affected cows. Administration of isoflupredone acetate did not affect epithelial cell percentage or SCC in milk.
  
  
  CONCLUSIONS
  During the early phase of endotoxin-induced mastitis in dairy cows, large numbers of epithelial cells were sloughed into the milk. Epithelial cell damage likely precedes an influx of immune cells into affected mammary glands and may contribute to breakdown of the blood-milk barrier.
authors.affiliation: Department of Veterinary Diagnostic and Production Animal Medicine, College of Veterinary Medicine, Iowa State University, Ames, IA 50011, USA.
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Wagner
authors.forename: Douglas E
authors.initials: DE
authors.lastname: Jones
authors.forename: Michael D
authors.initials: MD
authors.lastname: Apley
mesh_terms: D000818:Animals; D002417:Cattle; D003612:Dairying; D004731:Endotoxins / Q000633:toxicity*; D004847:Epithelial Cells / Q000166:cytology*; D005260:Female; D008414:Mastitis, Bovine / Q000139:chemically induced* / Q000150:complications; D008892:Milk / Q000166:cytology*
chemical_list: D004731:Endotoxins