Fig 4. Shift in pH, temperature and L-arginine availability influences L-arginine uptake.

H³L-arginine uptake was available after starvation or supplementation with 400 μM L-arginine at 25 and 34°C, and in pH 5.0 and pH 7.0. The transport was stopped with excess L-arginine, on ice, and washed 3-times with PBS. The cells were resuspended in scintillation liquid and scintillation count values were converted to pmol/min and normalized per number of parasites (1x10⁷). (a) p < 0.05, comparing the control and the changed conditions of starvation (-) or L-arginine supplementation (+) at 25°C or 34°C and in pH 5.0 or pH 7.0. (b) p < 0.05, comparing the changed conditions of starvation or L-arginine supplementation. (c) p < 0.05, comparing the changed conditions at 25°C or 34°C in pH 5.0 and pH 7.0. (d) p < 0.05, comparing the changed conditions at 25°C and 34°C in pH 5.0 or pH 7.0. The values are the mean ± SEM of three independent biological replicates.