Figure 1

Arginase and muscarinic receptors in TMps. Upper panel: macrophages from 7-day LMM3 tumor-bearing mice (TMps) were treated with carbachol (CARB) (100 nM) in the absence or presence of 100 μM N ^ω-hydroxy-L-arginine (NOHA), 1 μM atropine (AT), pirenzepine (PIR) or methoctramine (MET). Arginase activity was measured by urea production as μmol/h per 10⁶ cells. Values are means ± SEM for five experiments. **P < 0.001, *P < 0.05 compared with basal; NS, not significantly different from basal by Tukey's modified t-test. Lower panel: Western blot assay to detect arginase isoforms and muscarinic receptors (M) in lysates of TMps. The molecular masses of the bands indicated on the left are coincident with arginase I, II and M₁ and M₂ proteins. One representative experiment of three is shown.