Comparison of bronchoalveolar lavage fluid obtained from Mannheimia haemolytica-inoculated calves with and without prior treatment with the selectin inhibitor TBC1269

Objectives—To determine effects of selectin inhibitor TBC1269 on neutrophil infiltration, and neutrophilassociated injury during pneumonia induced by Mannheimia haemolytica and concentration of antimicrobial anionic peptide (AAP) in bronchoalveolar lavage fluid (BALF) as well as antimicrobial activity of BALF from healthy (control) neonatal calves, neonatal calves with M haemolytica-induced pneumonia, neonatal calves with prior treatment with TBC1269, and adult cattle. Animals—Eighteen 1- to 3-day-old calves and 9 adult cattle. Procedure—Calves were inoculated with M haemolyticaor pyrogen-free saline (0.14M NaCl) solution into the right cranial lung lobe, and BALF was collected 2 or 6 hours after inoculation. Thirty minutes before and 2 hours after inoculation, 4 calves received TBC1269. The BALF collected from 9 adult cattle was used for comparison of BALF AAP concentration and antimicrobial activity. Protein concentration and neutrophil differential percentage and degeneration in BALF were determined. A...