Fig 1. Nitric oxide synthase activity during Trypanosoma cruzi trypomastigotes adhesion to extracellular matrix.

Trypomastigotes (1x10⁹) were incubated with ECM (1.5 mg) in phenol red free-MEM, supplemented with 2% FBS, for 2 h at 37°C and 5% CO_2. The inhibitor L-NAME (10 mM) was added after the extract preparation. (A) •NO concentration in the medium was measured employing a modified fluorescent reaction of DAF-2 (Measure-iT High-Sensitivity Nitrite Assay Kit). (B) NOS activity was measured in T. cruzi extracts by the conversion of [³H]arginine to [³H]citrulline in T. cruzi extracts. The immunoblots were probed with anti-tubulin antibody to guarantee that the protein loading in each track was similar. The levels of intracellular L-Arginine (C) and L-citrulline (D) were obtained by the capillary electrophoresis method. Points marked with an asterisk represent a p<0.001 (one-way ANOVA) and with a dot represent p<0.001 in unpaired t-Student test. Results in (A) and (B) are the mean of three independent experiments and (C) and (D) are the mean of five independent experiments.