Vascular endothelial dysfunction has been demonstrated in obesity, but the molecular basis for this link has not been clarified. We examined the role of free fatty acids (FFA) on vascular reactivity in the obese fa/fa Zucker diabetic fatty (ZDF) rat. Addition of acetylcholine produced a dose-dependent relaxation in aortic rings of ZDF and lean +/+ rats, but the ED(50) value was higher in ZDF (-6.80 +/- 0.05 vs. -7.11 +/- 0.05 log(10) mol/liter, P = 0.033). A 2-wk treatment with a 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, pitavastatin (3 mg/kg/d) or a reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor, apocynin (5 mmol/liter in drinking water), improved the response in ZDF (ED(50), -7.16 +/- 0.03 and -7.14 +/- 0.05 log(10) mol/liter, P = 0.008 and P = 0.015 vs. vehicle, respectively). Vasodilator response to sodium nitroprusside was identical between ZDF and +/+ rats. Vascular reactive oxygen species (ROS) levels and NADPH oxidase activity in aorta were increased in ZDF rats but were decreased by pitavastatin. In in vitro cell culture, intracellular ROS signal and NADPH oxidase subunit mRNA were increased by palmitate, but this palmitate-induced ROS production was inhibited by NADPH oxidase inhibitor or pitavastatin. In conclusion, FFA-induced NADPH oxidase subunit overexpression and ROS production could be involved in the endothelial dysfunction seen in obese ZDF rats, and this could be protected by pitavastatin or NADPH oxidase inhibitors.

Vacuolar protein sorting 35 (VPS35) was recently reported to be a pathogenic gene for late-onset autosomal dominant Parkinson's disease (PD), using exome sequencing. To date, VPS35 mutations have been detected only in whites with PD. The aim of the present study was to determine the incidence and clinical features of Asian PD patients with VPS35 mutations. We screened 7 reported nonsynonymous missense variants of VPS35, including p.D620N, known as potentially disease-associated variants of PD, in 300 Japanese index patients with autosomal dominant PD and 433 patients with sporadic PD (SPD) by direct sequencing or high-resolution melting (HRM) analysis. In addition, we screened 579 controls for the p.D620N mutation by HRM analysis. The p.D620N mutation was detected in 3 patients with autosomal dominant PD (1.0%), in 1 patient with SPD (0.23%), and in no controls. None of the other reported variants of VPS35 were detected. Haplotype analysis suggested at least 3 independent founders for Japanese patients with p.D620N mutation. Patients with the VPS35 mutation showed typical tremor-predominant PD. We report Asian PD patients with the VPS35 mutation. Although VPS35 mutations are uncommon in PD, the frequency of such mutation is relatively higher in Japanese than reported in other populations. In VPS35, p.D620N substitution may be a mutational hot spot across different ethnic populations. Based on the clinical features, VPS35 should be analyzed in patients with PD, especially autosomal dominant PD or tremor-predominant PD.

Aims/hypothesis Nitric oxide (NO) is synthesised not only from L-arginine by NO synthases (NOSs), but also from its inert metabolites, nitrite and nitrate. Green leafy vegetables are abundant in nitrate, but whether or not a deficiency in dietary nitrite/nitrate spontaneously causes disease remains to be clarified. In this study, we tested our hypothesis that long-term dietary nitrite/nitrate deficiency would induce the metabolic syndrome in mice. Methods To this end, we prepared a low-nitrite/nitrate diet (LND) consisting of an amino acid-based low-nitrite/nitrate chow, in which the contents of L-arginine, fat, carbohydrates, protein and energy were identical with a regular chow, and potable ultrapure water. Nitrite and nitrate were undetectable in both the chow and the water. Results Three months of the LND did not affect food or water intake in wild-type C57BL/6J mice compared with a regular diet (RD). However, in comparison with the RD, 3 months of the LND significantly elicited visceral adiposity, dyslipidaemia and glucose intolerance. Eighteen months of the LND significantly provoked increased body weight, hypertension, insulin resistance and impaired endothelium-dependent relaxations to acetylcholine, while 22 months of the LND significantly led to death mainly due to cardiovascular disease, including acute Mika Kina-Tanada and Mayuko Sakanashi contributed equally to this work.

Results demonstrated that tetrahydrobiopterin lessens ischemia-reperfusion injury in isolated perfused rat hearts, probably independent of its intrinsic radical scavenging action. The cardioprotective effect of tetrahydrobiopterin implies that tetrahydrobiopterin could be a novel and effective therapeutic option in the treatment of ischemia-reperfusion injury.

Recent epidemiological studies have demonstrated that coffee drinking is associated with reduced mortality of cardiovascular disease. However, its precise mechanisms remain to be clarified. In this study, we examined whether single ingestion of caffeine contained in a cup of coffee improves microvascular function in healthy subjects. A double-blind, placebo-controlled, crossover study was performed in 27 healthy volunteers. A cup of either caffeinated or decaffeinated coffee was drunk by the subjects, and reactive hyperemia of finger blood flow was assessed by laser Doppler flowmetry. In an interval of more than 2 days, the same experimental protocol was repeated with another coffee in a crossover manner. Caffeinated coffee intake slightly but significantly elevated blood pressure and decreased finger blood flow as compared with decaffeinated coffee intake. There was no significant difference in heart rate between caffeinated and decaffeinated coffee intake. Importantly, caffeinated coffee intake significantly enhanced post-occlusive reactive hyperemia of finger blood flow, an index of microvascular endothelial function, compared with decaffeinated coffee intake. These results provide the first evidence that caffeine contained in a cup of coffee enhances microvascular function in healthy individuals.