Figure 2.
Response of alveolar macrophages (AM) and bone marrow-derived macrophages (BMM) to ricin. Immunoblot analysis of cell lysates from AM (upper left panel) or BMM (upper right panel) exposed to 100 or 1000 ng/ml ricin for 2 or 4 hrs. Antibodies used were reactive against phospho-p38 MAPK, phospho-JNK, phospho-ERK1/2, and p38 (used as a loading control). Lower panel: Inhibition of protein synthesis in BMM, measured by incorporation of [3H]-leucine 3 hrs after the addition of increasing concentrations of ricin. Each treatment was performed in triplicates. Data are presented as mean ± standard error of the mean. Asterisks show comparison between treatments and controls. NS, not significantly different; *, p<0.05; **, p<0.01; ***, p<0.001;