Attempt to pharmacologically modulate procoagulant activity of lipopolysaccharide-stimulated adherent bovine alveolar macrophages.

OBJECTIVE

To investigate the effects of anti-inflammatory drugs on lipopolysaccharide-induced procoagulant activity of bovine alveolar macrophages.

DESIGN

Procoagulant activity was induced in bovine alveolar macrophages from 4 healthy Holstein calves aged 6 to 16 weeks by incubation with lipopolysaccharide. 3 anti-inflammatory drugs were used at 4 concentrations and 3 times to pretreat the alveolar macrophages. Results were analyzed to determine whether drug, concentration, or exposure period had a significant (P > 0.05) effect.

PROCEDURE

Bovine alveolar macrophages, harvested by volume-controlled bronchoalveolar lavage, were pretreated for 30, 60, or 120 minutes with an anti-inflammatory compound (dexamethasone, flunixin meglumine, or phenylbutazone) at several concentrations ( 0, 1, 10, and 100 microM). Bovine alveolar macrophages were exposed to lipopolysaccharide (Escherichia coli O55:B5) in the presence and absence of fetal bovine serum for 4 hours. Procoagulant activity was measured, using a chromogenic assay.

RESULTS

None of the drugs was associated with a modification of procoagulant activity expression.

CONCLUSION

Use of these 3 anti-inflammatory drugs is unlikely to modify the extent of the fibrinous reaction commonly observed in cases of acute bovine respiratory tract disease complex.

CLINICAL RELEVANCE

The alveolar macrophage has a key role in fibrin production. Assuming in vivo events mimic the in vitro model, is appears unlikely that administration of anti-inflammatory drugs will reduce the procoagulant activity of the bovine alveolar macrophages and the directly associated pulmonary fibrosis.