REDUCTION OF ACYLOXYACYL HYDROLASE ACTIVITY IN CIRCULATING NEUTROPHILS FROM COWS AFTER PARTURITION

Citation
H. Dosogne et al., REDUCTION OF ACYLOXYACYL HYDROLASE ACTIVITY IN CIRCULATING NEUTROPHILS FROM COWS AFTER PARTURITION, Journal of dairy science, 81(3), 1998, pp. 672-677
Citations number
37
Categorie Soggetti
Agriculture Dairy & AnumalScience","Food Science & Tenology
Journal title
ISSN journal
00220302
Volume
81
Issue
3
Year of publication
1998
Pages
672 - 677
Database
ISI
SICI code
0022-0302(1998)81:3<672:ROAHAI>2.0.ZU;2-6
Abstract
Bovine neutrophils contain the enzyme acyloxyacyl hydrolase, which hyd rolyzes the acyloxyacyl linkage of the two nonhydroxylated fatty acyl chains to two 3-hydroxy fatty acids in the highly conserved lipid A pa rt of endotoxins with high specificity. This hydrolysis decreases the toxicity of lipid A, but the immunostimulatory capacity of endotoxins is largely maintained. In two trials, we studied the activity of acylo xyacyl hydrolase in neutrophils that had been isolated from the blood of 18 dairy cows around parturition. Between 10 and 26 d after parturi tion, the activity of acyloxyacyl hydrolase in neutrophils decreased a pproximately 20% below prepartum activity. At about 2 mo after parturi tion, acyloxyacyl hydrolase activity returned to prepartum values. Cha nges in acyloxyacyl hydrolase activity could not be attributed to chan ges in binding of lipopolysaccharides by the CD14 molecules on neutrop hils or monocytes. We hypothesize that decreased acyloxyacyl hydrolase activity in neutrophils shortly after parturition is a factor that in creases the susceptibility of dairy cows to coliform mastitis during e arly lactation.