Figure 2

Effects of BH4, L-arginine (L-arg) and vitamin C (VitC) on bioavailable NO in the ischemic gastrocnemius and gracilis muscles. Muscle was harvested 14 d after the induction of hindlimb ischemia, and supernatants from muscle homogenates were used in these assays. (A) Ca²⁺-dependent NOS activity was increased by all dietary additives, although the greatest increase was noted in mice receiving BH4 + L-arginine or BH4 + L-arginine + vitamin C. Data are means ± sd; n = 5–6. *p < 0.05 versus control; ^†p < 0.05 versus BH4 or L-arginine groups. (B) Ca²⁺-independent NOS activity was less in mice receiving BH4 + L-arginine or BH4 + L-arginine + vitamin C than in control mice. Data are means ± sd; n = 5–6. *p < 0.05 versus control. (C, D) NOx was increased in gastrocemius (C) and gracilis (D) in mice receiving BH4 + L-arginine or BH4 + L-arginine + vitamin C. Data are means ± sd; n = 5. *p < 0.05 versus control; ^†p < 0.05 versus BH4 or L-arginine group. In all graphs, control rats were fed normal chow and underwent hindlimb ischemia, whereas the four treatment groups consumed diets supplemented with additives noted in the bar graph. Concentrations of these additives are noted in the text.