Figure 5.

Tylvalosin inhibits the production of the pro-inflammatory lipid mediator LTB₄, in calcium ionophore-activated porcine neutrophils. (A) Secreted levels of LTB₄ from porcine neutrophils treated with 10% HI-FBS in HBSS (control) or 10 μg/mL TVN in the presence or absence of 3 μM calcium ionophore A23187 for 0.5 h were measured using reverse phase- high performance liquid chromatography (RP-HPLC). Values represent fold change of LTB₄ peak integration values generated from arbitrary units on sample specific chromatograms where intensity correlated to LTB₄ concentration. Data represent mean ± SEM (n = 7–10/group). **P < 0.01 versus unstimulated control; ^#P < 0.05 versus 3 μM A23187. (B) Porcine neutrophils underwent these same treatments for 0.5 h and LTB₄ release was measured using liquid chromatography-mass spectrometry (LC/MS). Values represent LTB₄ levels in pM calculated from standard curves generated by integrating the area under the curve of elution peaks where intensity correlated to known LTB₄ concentrations. Data represent mean ± SEM (n = 10–15/group). ***P < 0.001 versus unstimulated control; ^##P < 0.01 versus 3 μM A23187.