thromboxane-b2 and Mastitis--Bovine

One hind quarter of 27 healthy lactating cows was infused with 100 microg Escherichia coli endotoxin. Two hours later, nine of the cows were given physiological saline by intramuscular injection, nine were given 4 mg/kg ketoprofen orally, and nine were given 3 mg/kg ketoprofen by intramuscular injection. Ketoprofen administered either orally or parenterally significantly reduced the effect of the endotoxin on rectal temperature, ruminal contractions and respiratory rate. The size of the udder, the signs of pain and the concentrations of thromboxane B2, especially in plasma, were also reduced, and the appearance of their milk was almost normal. The response of cows to the oral treatment was as rapid as it was to intramuscular treatment.

Topics: Administration, Oral; Animals; Anti-Inflammatory Agents, Non-Steroidal; Body Temperature; Cattle; Endotoxins; Female; Injections, Intramuscular; Ketoprofen; Lactation; Mastitis, Bovine; Milk; Pain; Pain Measurement; Thromboxane B2

Acute Escherichia coli mastitis is one of the major sources of economic loss in the dairy industry due to reduced milk production, treatment costs, discarded milk, and occasional fatal disease. Nonsteroidal anti-inflammatory drugs (NSAIDs) are frequently used as adjunctive therapy to antibiotics. The objective of the current study was to evaluate the effect of carprofen treatment following infusion of Escherichia coli into the mammary glands of primiparous cows during the periparturient period. Severity of mastitis was scored based on the average milk production in the uninfected quarters on d +2 postinoculation and a clinical severity score. Carprofen was administered intravenously at 9 h postchallenge, when clinical signs of mastitis appeared. In previous work, efficacy of NSAIDs was mainly evaluated using clinical symptoms. In the present study, the effect of carprofen on innate immune response was also assessed by quantification of inflammatory mediators. All primiparous cows reacted as moderate responders throughout the experimental period. Primiparous cows were intramammarily inoculated with 1 x 10(4) cfu of E. coli P4:O32 in 2 left quarters. Analysis of blood and milk parameters, including IL-8, complement component C5a, lipopolysaccharide-binding protein (LBP), soluble CD14, prostaglandin E2, and thromboxane B2 was performed from d 0 to d +6 relative to intramammary inoculation. Rectal temperature in carprofen-treated animals was lower than in control animals at 3 and 6 h posttreatment. Treatment also restored the decreased reticulorumen motility that occurs during E. coli mastitis to preinfection levels faster than in control animals. Carprofen treatment resulted in an earlier normalization of the clinical severity score. Eicosanoid (prostaglandin E2 and thromboxane B2) production in milk tended to be inhibited by carprofen. No significant differences in the kinetic patterns of somatic cell count, IL-8, complement component C5a, LBP, and soluble CD14 were observed. In conclusion, carprofen treatment improved general clinical condition by effective antipyrexia and restoration of reticulorumen motility but did not significantly inhibit eicosanoid production. Carprofen treatment did not result in a significant decrease of chemotactic inflammatory mediators, IL-8 and C5a, and early innate immune molecules, sCD14 and LBP. Therefore, major modulatory effects from NSAID administration were not observed in this mastitis model, although a larger study mig

Topics: Animals; Anti-Inflammatory Agents, Non-Steroidal; Carbazoles; Cattle; Cell Count; Colony Count, Microbial; Complement C5a; Dinoprostone; Escherichia coli Infections; Female; Hematocrit; Interleukin-8; Lactation; Leukocyte Count; Lipopolysaccharide Receptors; Mastitis, Bovine; Milk; Parity; Pregnancy; Thromboxane B2

The effect of selenium deficiency on the product profile of arachidonic acid oxidation by enzymatic pathways in Holstein cows with experimentally-induced coliform mastitis was investigated. The animals were fed dairy rations containing 0.05 mg Se/kg dry matter, with the supplemented group receiving additional Se to increase the dietary concentration to approximately 0.35 mg Se/kg dry matter. Cows were inoculated intracisternally with 30 colony-forming-units of Escherichia coli at 14-16 weeks of lactation. Eicosanoids and bacteria numbers were recorded at various intervals of time for 60 h postinoculation. Milk from cows fed the Se-depleted diet had significantly higher (p less than 0.05) concentrations of TXB2 between 24 and 48 h and 6-keto-PGF1 alpha between 24 and 60 h postinoculation. Milk PGE2 concentration was significantly higher in the Se-deficient group at 24 h, whereas LTB4 was higher between 36 and 60 h postinoculation in the Se-deficient cows (p less than 0.05). Milk bacteria numbers were significantly higher between 16 and 24 h postinoculation in the Se-deficient group and three of the four cows in this group required euthanasia, whereas all four cows in the Se-supplemented group recovered without therapeutic intervention. These data indicate marked effects of dietary Se on milk eicosanoid concentrations in response to an E. coli infection. The changes in eicosanoid concentrations may be associated with the altered pathogenesis and outcome of mastitis in a Se-deficient state.

Topics: 6-Ketoprostaglandin F1 alpha; Administration, Oral; Animals; Cattle; Deficiency Diseases; Dinoprostone; Eicosanoids; Escherichia coli Infections; Leukotriene B4; Mastitis, Bovine; Milk; Selenium; Thromboxane B2; Time Factors; Treatment Outcome

Milk levels of free fatty acids (FFA) and prostaglandins (PGs) were determined in healthy cows and in those with mastitis and compared with some parameters commonly used for diagnosing mastitis. A modified gas chromatography-mass spectrometry method was used. In mastitis there was a substantial overall increase in FFA levels in milk. Specific attention was paid to the fate of the long-chain polyunsaturated fatty acids, known as precursors for the production of PGs, leukotrienes and other eicosanoids. Both the omega-6 and omega-3 lines of these lipids were increased in mastitis, but only in proportion to other FFA. The milk levels of PGs (PGF2, PGF2 alpha, thromboxane B2) were elevated in the same proportion. The possible importance of lipid peroxidation, inflammatory reaction and host defence are evaluated in relation to tissue destruction and oxidative killing of pathogens. It may be possible to manipulate the intake and fate of FFA in the organism by dietary intake, antioxidants and proper storing of feed. It is concluded that in studies concerning FFA special attention should be given to those long-chain fatty acids that are precursors for the formation of eicosanoids.

Topics: Animals; Cattle; Fatty Acids, Nonesterified; Gas Chromatography-Mass Spectrometry; Lipid Peroxidation; Mastitis, Bovine; Milk; Prostaglandins; Thromboxane B2

Cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP) concentrations in milk and plasma samples from healthy and mastitic cows were determined by radioimmunoassay and compared with prostaglandins (PGE2, PGF2 alpha and thromboxane B2 [TXB2]), phospholipids and other relevant parameters in milk and blood. The concentrations of cAMP were about five times higher in plasma (p less than 0.01) than in milk, whereas the cGMP concentration in milk was three times higher (p less than 0.01) than that in plasma in both healthy and diseased animals. In mastitic milk, the cAMP and cGMP concentrations were 19% and 65% and in blood plasma 13% and 84% higher respectively than in healthy animals. In milk, cyclic nucleotide concentrations correlated with the markedly elevated cell count and also with the prostaglandin concentration and pH. In blood, cAMP correlated positively with phospholipids and cGMP with reduced glutathione (GSH). These changes are considered to be important in the disease process and, in particular, the increase in cGMP deserves further study.

Topics: Animals; Cattle; Cyclic AMP; Cyclic GMP; Female; Glutathione; Hydrogen-Ion Concentration; Mastitis, Bovine; Milk; Phospholipids; Prostaglandins; Radioimmunoassay; Thromboxane B2

By inoculating Klebsiella pneumoniae into the teat canals of mammary glands, coliform mastitis was induced experimentally in 6 lactating cows. Release of eicosanoids, histamine, and serotonin in plasma and milk was studied in response to 2 doses of K pneumoniae. A low dose (mean, 5,000 organisms/ml) was inoculated into cows 1 through 4, and a high dose (mean, 200,000 organisms/ml) was inoculated into cows 5 and 6. Milk and blood samples were collected before inoculation (0 hours), and hourly, from 3 to 24 hours after inoculation. Concentrations of prostaglandin F2 alpha (PGF2 alpha), prostaglandin E (PGE), thromboxane B2 (TxB2), histamine, and serotonin were measured in plasma and milk obtained from control (NaCl solution-inoculated) and infected quarters. Fluorometric analysis of milk from infected quarters revealed significantly increased histamine and serotonin concentrations regardless of the dose of K pneumoniae. The mean (+/- SEM) peak concentrations of histamine were significantly (P less than 0.01) increased from the preinoculation value of 44 (+/- 12) ng/ml to 312 (+/- 104) ng/ml in milk from infected quarters and 72 (+/- 24) ng/ml in milk from control quarters. The mean peak concentration of serotonin increased significantly from the preinoculation concentration of 436 (+/- 37) ng/ml to 1,754 (+/- 662) ng/ml and 4,867 (+/- 1,248) ng/ml in milk from control (P less than 0.02) and infected (P less than 0.001) quarters, respectively. However, serotonin concentration in milk from infected quarters was approximately 2.8 times greater than that in milk from control quarters. Concentrations of PGF2 alpha, PGE, and TxB2 in milk and plasma were evaluated by radioimmunoassay.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Animals; Cattle; Dinoprost; Female; Histamine; Histamine Release; Klebsiella Infections; Klebsiella pneumoniae; Mastitis, Bovine; Milk; Prostaglandins E; Prostaglandins F; Serotonin; Thromboxane B2

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.

Topics: Animals; Cattle; Dinoprost; Dinoprostone; Electric Conductivity; Female; Mastitis, Bovine; Milk; Prostaglandins E; Prostaglandins F; Radioimmunoassay; Thromboxane B2

Arachidonic acid metabolites (AAM) were measured in milk and plasma during the course of acute endotoxin-induced mastitis in 12 lactating cows. Mastitis was induced by intramammary challenge exposure with 10 micrograms of Escherichia coli (026:B6) endotoxin. Endotoxin was injected into the teat cistern via the teat canal of a single randomly selected rear quarter of each cow. Concentrations of prostaglandin (PG) F2 alpha and thromboxane (Tx) B2 in fat-free unextracted milk and of 15-keto-13,14-dihydro-PGF2 alpha in plasma were measured by radioimmunoassay. Total production of AAM in milk was determined by measuring quarter milk production. The AAM were compared in 6 cows administered flunixin meglumine (1.1 mg/kg of body weight) and in 6 cows administered saline solution. Concentrations of TxB2 in milk were significantly (P less than 0.001) increased during the early course of acute mastitis in endotoxin-treated quarters of cows not administered flunixin meglumine. Peak concentrations of TxB2 in milk occurred at 8 hours after endotoxin inoculation. Flunixin meglumine treatment produced significant (P less than 0.05) reductions in milk TxB2 and plasma 15-keto-13,14-dihydro-PGF2 alpha concentrations. Concentrations of PGF2 alpha in milk and total PGF2 alpha and TxB2 production per quarter per milking were not significantly influenced by endotoxin challenge or by flunixin meglumine treatment.

Topics: Animals; Arachidonic Acid; Arachidonic Acids; Cattle; Clonixin; Dinoprost; Endotoxins; Escherichia coli; Female; Mastitis, Bovine; Milk; Nicotinic Acids; Prostaglandins F; Thromboxane B2

Prostaglandin (PG) levels in milk and plasma samples from mastitic cows were determined by radioimmunoassay and compared with erythrocyte glutathione peroxidase (GSH-Px) and other relevant parameters in milk and blood. The overall levels of PGE2, PGF2 alpha and thromboxane B2 (TXB2) in milk were two to four times higher than in blood plasma both in healthy and diseased animals (P less than 0.01). In mastitic milk the PG levels were 24 to 55 per cent and in blood plasma 41 to 95 per cent higher than in healthy animals. The changes were significant and largest for the PGF2 alpha values. In milk, the PG concentrations correlated with the markedly elevated cell count (r = 0.49 to 0.57), and TXB2 values also correlated with milk yield. In blood, PGE2 and PGF2 alpha correlated positively with serum albumin, and PGE2 also correlated with glutathione (GSH). PGE2 and PGF2 alpha correlated negatively with GSH-Px and gamma-glutamyl transferase. The substantial decline in GSH-Px in mastitic animals (P less than 0.01) may be related to changes in lipid peroxidation and PG formation. The possible implications of these findings in the treatment of mastitis are discussed.

Topics: Animals; Cattle; Dinoprost; Dinoprostone; Erythrocytes; Female; Glutathione Peroxidase; Mastitis, Bovine; Milk; Prostaglandins E; Prostaglandins F; Radioimmunoassay; Thromboxane B2

Concentrations of prostaglandin F2 alpha (PGF2 alpha) and thromboxane B2 (TXB2) were evaluated in the milk of cows with naturally occurring (n = 3) and experimentally induced (n = 5) acute coliform mastitis. These arachidonic acid metabolites were measured by radioimmunoassay in unextracted milk. Experimental infections were induced by inoculating 600 to 1,200 colony-forming units of Escherichia coli into 1 mammary quarter per experimental cow. In the experimental cows, milk was collected before inoculation and at 12, 24, 36, 48, 60, and 72 hours after inoculation. Somatic cell concentrations, bovine serum albumin, and concentrations of PGF2 alpha and TXB2 were determined in milk collected at each sampling. Mild-to-moderate increases in milk PGF2 alpha and TXB2 concentrations were observed in cows with naturally occurring mastitis. the increases corresponded to the clinical severity and course of mastitis. In the experimental cows, increases in milk PGF2 alpha and TXB2 concentrations were observed, but the increases were not significant, using a statistical model that included factors of treatment, cows, hours after inoculation, cows-by-treatment and hours-by-treatment interactions, and random error (residual). Results of the present study indicated a large biological variability in milk arachidonic acid metabolite concentrations in cows with acute coliform mastitis, and that arachidonic acid metabolites may be important in the pathophysiologic process of acute coliform mastitis.

Topics: Acute Disease; Analysis of Variance; Animals; Arachidonic Acid; Arachidonic Acids; Cattle; Dinoprost; Escherichia coli Infections; Female; Lactation; Mastitis, Bovine; Milk; Pregnancy; Prostaglandins F; Radioimmunoassay; Thromboxane B2; Thromboxanes