FIG 5.

Tulathromycin inhibits LTB₄ production in bovine neutrophils, at least in part, via inhibition of PLA₂ activity in vitro. Secreted levels of LTB₄ from bovine neutrophils treated with HBSS (ctrl) or 2 mg/ml tulathromycin (TUL) for 1.0 h at 37°C in the presence (+) or absence (−) of a 3 μM concentration of the calcium ionophore A23187 and 3 μM exogenous arachidonic acid (AA) are indicated. Values are the mean ± SEM (n = 3/group). *, P < 0.05 versus unstimulated control; #, P < 0.01, and ##, P < 0.001, versus A23187-stimulated control; $, P < 0.05 versus A23187- and AA-stimulated control.