FIG. 2.

Catalase C-10 inhibits production of both RNI and citrulline by IFN-γ- and LPS-activated J774.16 macrophages. Experiments were carried out as described in footnote a of Table 1, except that, at the end point of the studies, both RNI and citrulline contents were assayed as previously described (11, 12). Catalase C-10 and C-3155 were used at a final concentration of 2,600 U/ml. The ability of C-10 to inhibit production of RNI is apparent at concentrations as low as 250 U/ml (data not shown). Data derived from three independent experiments are shown. Error bars indicate standard errors. Asterisks indicate a P value of <0.05 (one-way analysis of variance; controls were samples without catalase).