Induction of peroxisomal enzymes and a 64-kDa peptide in cultured mouse macrophages treated with clofibrate

The presence of catalase-containing particles was demonstrated in mouse macrophages of the cell line J774.3. These cells were incubated with clofibrate, a hypolipidemic drug known to cause peroxisome proliferation in rodent hepatocytes. The specific activities of catalase and fatty acid oxidase were significantly increased after 48 h incubation with 2 mM clofibrate. This response proved to be time and dose dependent. Other organelle marker enzymes showed little change in activity. Unexpectedly, clofibrate treatment also produced an increase in a 64-kDa peptide in these cells.