Coronary vasodilation is impaired in the postischemic heart with a loss of endothelial nitric oxide synthase (eNOS) activity, but the mechanisms underlying ischemia-induced eNOS dysfunction are not understood. For nitric oxide (NO) synthesis, eNOS requires the redox-sensitive cofactor tetrahydrobiopterin (BH(4)); however, the role of BH(4) in ischemia-induced endothelial dysfunction remains unk...

We previously reported that small mesenteric arteries from hypertensive rats have increased NOS-derived H(2)O(2) and reduced NO/cGMP signaling. We hypothesized that antihypertensive therapy lowers blood pressure through a tetrahydrobiopterin (BH(4))-dependent mechanism restoring NO/cGMP signaling and endothelial NOS (NOS3; eNOS) phosphorylation in small arteries. To test this hypothesis, small ...

Tetrahydrobiopterin (BH(4)) is a required cofactor for the enzymatic activity of phenylalanine hydroxylase (PAH) and is synthesized de novo from GTP in several tissues. Heterologous expression of PAH in tissues other than liver is a potential novel therapy for human phenylketonuria that is completely dependent upon BH(4) supply in the PAH-expressing tissue. Previous experiments with liver PAH-d...

have been no investigations on the roles of NO and BH 4 in CAPD. Therefore, we measured both NO and BH 4 concentrations in spent dialysates of CAPD patients to investigate the relation between the two. The NO concentration was measured by an NO sensor [6, 12] and BH 4 and BH 2 concentrations were measured fluorometrically by the HPLC-based method [13] . This study protocol was approved by the E...

have been no investigations on the roles of NO and BH 4 in CAPD. Therefore, we measured both NO and BH 4 concentrations in spent dialysates of CAPD patients to investigate the relation between the two. The NO concentration was measured by an NO sensor [6, 12] and BH 4 and BH 2 concentrations were measured fluorometrically by the HPLC-based method [13] . This study protocol was approved by the E...

BACKGROUND Platelet-derived nitric oxide inhibits platelet aggregation via constitutive NO synthase (NOS). Tetrahydrobiopterin (BH(4)), a cofactor of NOS, augments NO formation, whereas its deficiency decreases NO bioactivity and increases superoxide generation by NOS. The roles of intraplatelet BH(4) in platelet aggregation and thrombus formation, however, are unknown. Accordingly, we investig...

Previous studies suggested that loss of tetrahydrobiopterin (BH(4)) may play an important role in the pathogenesis of vascular endothelial dysfunction induced by diabetes and hypertension. In contrast, controversial results have been reported regarding BH(4) metabolism in experimental models of atherosclerosis. Therefore, the present study was designed to characterize the expression and activit...

BACKGROUND Bochdalek hernia (BH) is generally congenital, presenting with respiratory distress. However, this pathology is rarely detected in adults. Some adult cases of BH present with symptoms attributed to the hernia, but incidental detection of BH is increasing among asymptomatic adults due to advances in imaging modalities. This report presents the management of incidental BH patients dete...

Effects of phenylalanine and diand tetrahydropterins on presteady-state and steady-state catalytic behavior of rat liver phenylalanine hydroxylase are analyzed. From this and previous work (Shiman, R, Xia, T., Hill, M., and Gray, D. (1994) J. BioZ. Chem. 269, 2464724656), which analyzed binding of the same compounds to the enzyme in the absence of catalysis, a model of phenylalanine hydroxylase...

Let BH = {BH (t), t ∈ RN } be an (N, d)-fractional Brownian sheet with index H = (H1, . . . , HN ) ∈ (0, 1)N . The uniform and local asymptotic properties of BH are proved by using wavelet methods. The Hausdorff and packing dimensions of the range BH ([0, 1]N), the graph GrBH ([0, 1]N) and the level set are determined.