Figure 7.

Improvement of endothelial function ex vivo by sepiapterin and in vivo by BH₄. The effects of sepiapterin (100 µmol/L), a BH₄ precursor, and polyethylene glycolated-superoxide dismutase (100 U/mL) pretreatment of aortic rings from angiotensin-II (AT-II)–infused rats (A) or spontaneously hypertensive rats (SHR, B) for 1 h were determined in separate experiments. Data shown are representative for at least three animals or at least six aortic rings/group. p < 0.05: * vs. WKY/Control; ^$ vs. AT-II/BH₄. The statistics were based on one-way-ANOVA comparison of pD₂-values and efficacies but also on comparisons of all concentrations in all groups by two-way-ANOVA analysis (for sake of clarity significance is not shown for all data points). From Schuhmacher et al., Hypertension 2010 [230]. With permission of Wolters Kluwer Health, Inc. (Philadelphia, PA, USA). Copyright © 2010, Wolters Kluwer Health (Philadelphia, PA, USA). (C) Effect of tetrahydrobiopterin (BH₄) and tetrahydroneopterin (NH₄) on the acetylcholine (ACh) dose-response relationship in chronic smokers. BH₄ significantly improved ACh dose-response relationship, whereas NH₄ was ineffective. Modified from Heitzer et al., Circ. Res. 2000 [233] and published in Schulz et al. Antioxid. Redox Signal. 2008 [119]. With permission of Mary Ann Liebert, Inc. (New Rochelle, NY, USA). Copyright © 2008, Mary Ann Liebert, Inc. (New Rochelle, NY, USA).