Milk prostaglandins and electrical conductivity in bovine mastitis

Abstract

Prostaglandin (PG) levels in milk samples from healthy and mastitic cows were determined by radioimmunoassay. In composite milk the PG levels were rather high both in healthy and mastitic samples, and the only significant difference was in thromboxane B2 (TXB). In quarter milk samples classified according to the degree of mastitis by use of somatic cell counts, PGE2 was 40, PGF2 alpha 15, and TXB2 44 per cent higher respectively in affected samples. PG levels were in good correlation with somatic cell counts (r = 0.63-0.68, p less than 0.01) and electrical conductivity (r = 0.36-0.52, p less than 0.01), two established criteria for diagnosis of mastitis. PGE2 also correlated with protein, TXB2 with fat content. PGF 2 alpha was in a negative correlation with milk yield. The good correlation of PGs with somatic cell counts and electrical conductivity suggests that PGs might be used as markers of mastitic inflammation.

Pathogen-dependent induction of cytokines and other soluble inflammatory mediators during intramammary infection of dairy cows1

“…Increases in leukotriene B 4 and PGF 2α have also been detected in milk obtained from cows experimentally infected with another gramnegative pathogen, K. pneumoniae (Zia et al, 1987;Rose et al, 1989); however, Zia et al (1987) failed to detect significant increases in PGE 2 or thromboxane A 2 , which they also ascribed to large animal variability. Gram-positive pathogens can also evoke an eicosanoid response, because increases in PGE 2 , PGF 2α , and thromboxane B 2 have been detected in milk samples obtained from naturally occurring cases of mastitis, in which the causative agent was identified as either S. uberis, S. aureus, S. dysgalactiae, or Micrococcus species (Atroshi et al, 1986(Atroshi et al, , 1987. Similarly, in chronic cases of mastitis caused by coagulase-negative staphylococci, S. uberis, S. agalactiae, or S. aureus, increases in leukotriene B 4 have been detected in quarters infected with these gram-positive bacteria (Boutet et al, 2003).…”