Fig. 8.

Interference of tamoxifen on inositol uptake of L. amazonensis promastigotes. (A) Effect of tamoxifen (10, 30, and 50 μM) on myo-inositol uptake at Km (200 μM myo-inositol plus 0.3 μCi myo-[³H]-inositol) and V_max (2000 μM myo-inositol plus 0.3 μCi myo-[³H]-inositol) conditions. Unlabeled 2 mM myo- and scyllo-inositol were used as inhibitors at the Km condition. (B) myo-inositol uptake kinetics in L. amazonensis promastigotes treated with different concentrations of tamoxifen. Inset: Double reciprocal plot of the linear inhibition of inositol uptake at the different concentrations of tamoxifen compared to untreated control. The uptake assays were conducted with increasing substrate concentrations (50, 100, 200, 500, 1000 and 2000 μM myo-inositol plus 0.3 μCi myo-[³H]-inositol) during a fixed time of 2 min. Results are representative of three experiments performed in each case. The bars represent the standard deviation of duplicates or triplicates. The myo-inositol incorporations is shown as picomoles per minute per 3 × 10⁷ promastigotes.