Fig. 4.
Reactive oxygen species (ROS) mediate enhanced vasoconstrictor sensitivity in lungs from chronic hypoxia (CH) neonates: changes in total (A), arterial (B), and venous (C) resistance (mmHg·mL−1·kg·min) to 9,11-dideoxy-9α,11α-methanoepoxy prostaglandin F2α (U-46619) in lungs from control and CH neonates. Inset in C uses a smaller y-axis scale to allow better visualization of differences between groups. Experiments were conducted in the presence of the ROS scavenger 1-oxyl-2,2,6,6-tetramethyl-4-hydroxypiperidine (TEMPOL, 1 mM) or vehicle. All experiments were conducted in the presence of Nω-nitro-l-arginine (300 μM). Values are means ± SE; n = 6 rats for control vehicle, n = 5 rats for CH vehicle, n = 6 rats for control + TEMPOL, n = 4 rats for CH + TEMPOL. *P < 0.05 vs. control, #P < 0.05 vs. vehicle, analyzed by 2-way ANOVA at each U-46619 concentration ([U-46619]) with a Student-Newman-Keuls post hoc comparison.