Figure 7 .

Effect of L-citrulline and inhibition of argininosuccinate lyase (ASL) on TSM relaxation in hyperoxia-exposed rat pups: The addition of 2 mM L-citrulline reversed the hyperoxia-induced impairment of relaxation of TSM (p < 0.001). The effect of the L-citrulline was lost when TSM was incubated in the presence of argininosuccinate lyase (ASL) inhibitor, L-succinate (1 mM) (p < 0.01). *Hyperoxia vs. Room air; §Hyperoxia + L-citrulline vs. Hyperoxia; †Hyperoxia + L-citrulline + succinate vs. Hyperoxia + L-citrulline. *p < 0.05; ***p < 0.001; §§p < 0.01; §§§p < 0.001; †p < 0.05; ††p < 0.01(n = 7 for each protocol of the experiments).