ATTEMPT TO PHARMACOLOGICALLY MODULATE PROCOAGULANT ACTIVITY OF LIPOPOLYSACCHARIDE-STIMULATED ADHERENT BOVINE ALVEOLAR MACROPHAGES

Objective-To investigate the effects of anti-inflammatory drugs on lip opolysaccharide-induced procoagulant activity of bovine alveolar macro phages. Design-Procoagulant activity was induced in bovine alveolar ma crophages from 4 healthy Holstein calves aged 6 to 16 weeks by incubat ion with lipopolysaccharide. 3 anti-inflammatory drugs were used at 4 concentrations and 3 times to pretreat the alveolar macrophages. Resul ts 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, w ere pretreated for 30, 60, or 120 minutes with an anti-inflammatory co mpound (dexamethasone, flunixin meglumin, or phenylbutazone) at severa l concentrations (0, 1, 10, and 100 mu M). Bovine alveolar macrophages were exposed to lipopolysaccharide (Escherichia coil O55:B5) in the p resence and absence of fetal bovine serum for 4 hours. Procoagulant ac tivity was measured, using a chromogenic assay. Results-None of the dr ugs was associated with a modification of procoagulant activity expres sion. Conclusion-Use of these 3 anti-inflammatory drugs is unlikely to modify the extent of the fibrinous reaction commonly observed in case s of acute bovine respiratory tract disease complex. Clinical Relevanc e-The alveolar macrophage has a key role in fibrin production. Assumin g in vivo events mimic the in vitro model, is appears unlikely that ad ministration of anti-inflammatory drugs will reduce the procoagulant a ctivity of the bovine alveolar macrophages and the directly associated pulmonary fibrosis.