title: Serum amyloid A and TNF alpha in serum and milk during experimental endotoxin mastitis.
abstract: A cross-over study was conducted to investigate the effect of intramammarily infused lipopolysaccharide (LPS) on the acute phase reaction in early (EL) and in late (LL) lactation. Nine cows received intramammary injections of 100 microg of Escherichia coli 0111:B4 LPS during EL and LL. The severity of each cows systemic and local signs and change in milk appearance were recorded and scored throughout the experiment. Systemic and local signs were found to be more serious in EL cows. Tumor necrosis factor alpha (TNF alpha) was detected in milk but not in serum. Serum amyloid A (SAA) concentrations increased both in serum and in milk. The milk TNF alpha concentrations peaked at 8 h post-challenge (PC). SAA concentrations started to increase at 8 h PC, and peak concentrations were seen at 32 and 48 h PC in milk and serum, respectively. The milk TNF alpha and SAA seemed to be correlated, being on average higher in EL. Serum SAA concentration was not correlated with milk TNF alpha or SAA, nor with the severity of local or systemic signs, but was correlated with changes in milk appearance.
authors.affiliation: Department of Clinical Veterinary Science, Faculty of Veterinary Medicine, University of Helsinki, 04920 Saarentaus, Finland. tanja.lehtolainen@helsinki.fi
authors.forename: Tanja
authors.initials: T
authors.lastname: Lehtolainen
authors.forename: Christine
authors.initials: C
authors.lastname: Røntved
authors.forename: Satu
authors.initials: S
authors.lastname: Pyörälä
mesh_terms: D000818:Animals; D002417:Cattle; D005260:Female; D008070:Lipopolysaccharides; D008414:Mastitis, Bovine / Q000097:blood / Q000139:chemically induced / Q000378:metabolism*; D008892:Milk / Q000378:metabolism*; D011897:Random Allocation; D000685:Serum Amyloid A Protein / Q000378:metabolism*; D013997:Time Factors; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis* / Q000378:metabolism*
chemical_list: D008070:Lipopolysaccharides; D000685:Serum Amyloid A Protein; D014409:Tumor Necrosis Factor-alpha; C036757:lipopolysaccharide B