Fig. 2.

Plasma NOx levels in control (normoxic) and chronically hypoxic piglets. Plasma NOx levels were greater in chronically hypoxic piglets receiving high-dose oral BH₄ (sapropterin dihydrochloride) treatment (n = 7) than in normoxic control piglets (n = 9), untreated chronically hypoxic piglets (n = 9), or in piglets receiving low-dose oral BH₄ treatment (n = 4). Values are means ± SE. Different from *control (normoxic), +untreated chronic hypoxic, and !low-dose BH₄-treated chronic hypoxic: P < 0.05; ANOVA with post hoc comparison test.