Fig 6.

The proapoptotic effect of tulathromycin in bovine macrophages in vitro is caspase dependent. Levels of mono- and oligonucleosomes in bovine macrophages incubated with IMDM alone (control [ctrl]) or treated with tulathromycin (TUL; 1 mg/ml) for 12 h at 37°C in the absence or presence of LPS (1 μg/ml). Cells were pretreated with a 50 μM concentration of a pan-caspase inhibitor (ZVAD) or a DMSO vehicle control for 1.0 h at 37°C prior to treatment. There was no significant difference between any of the groups treated with ZVAD. Values were calculated as absorbance ratios versus values measured in control macrophages arbitrarily set to 1.0. Values are means ± SEM. n = 6 to 8/group. *, P < 0.001 versus unstimulated control; #, P < 0.05 versus LPS-stimulated control.