EFFECTS OF 4-IPOMEANOL ON BOVINE ALVEOLAR MACROPHAGE FUNCTION

The objective of this study was to determine whether 4-ipomeanol toxic osis in calves impairs alveolar macrophage functions important in pulm onary defense against infectious agents, Male Holstein calves were giv en either 4-ipomeanol (3 mg kg(-1), i.v.) or vehicle (polyethylene gly col 400). Alveolar macrophages were recovered by pulmonary lavage 3 da ys later, and their capacities to phagocytose and kill E. coli, migrat e toward zymosan-activated immune bovine serum, and produce interferon and interleukin-l activity were evaluated in vitro. Alveolar macropha ges recovered from 4-ipomeanol-treated calves had over a 70% decrease (p < 0.01) in chemotactic activity and over a 37% decrease (p < 0.005) in their capacity to phagocytose E. coli as compared to macrophages f rom control calves. Interleukin-l activity in macrophages from 4-ipome anol-treated calves tended to be higher than that from control calves, but the differences were not statistically significant (p = 0.06). 4- ipomeanol did not affect macrophage bactericidal activity or productio n of interferon. These results indicate that 4-ipomeanol suppresses se lect functions of alveolar macrophages in cattle that may be important in pulmonary defense against bacterial pathogens. (C) 1997 Elsevier S cience B.V.