Endothelial dysfunction is the earliest pathologic alteration in diabetic vascular injury and plays a critical role in the development of atherosclerosis. Plasma levels of adiponectin (APN), a novel vasculoprotective adipocytokine, are significantly reduced in diabetic patients, but its relationship with endothelial dysfunction remains unclear. The present study aims to determine whether APN deficiency may cause endothelial dysfunction and to investigate the involved mechanisms. Vascular rings were made from the aortic vessels of wild type (WT) or APN knockout (APN -/-) mice. Endothelial function, total NO production, eNOS expression/phosphorylation, superoxide production, and peroxynitrite formation were determined. ACh and acidified NaNO 2 (endothelial dependent and independent vasodilators, respectively) caused similar concentration-dependent vasorelaxation in WT vascular rings. APN -/-rings had a normal response to acidified NaNO 2 , but a markedly reduced response to ACh (>50% reduction vs. WT, P<0.01). Both superoxide and peroxynitrite production were increased in APN -/-vessels (P<0.01 vs. WT). Pretreatment with superoxide scavenger Tiron significantly, but incompletely restored vascular vasodilatory response to ACh. In APN -/-vessels, eNOS expression was normal, but NO production and eNOS phosphorylation was significantly reduced (P<0.01 vs. WT). Treatment of APN -/-mice in vivo with the globular domain of adiponectin reduced aortic superoxide production, increased eNOS phosphorylation, and normalized vasodilatory response to ACh. Increased NO inactivation combined with decreased basal NO production contribute to endothelial dysfunction development when there is a paucity of APN production. Interventions directed towards increasing plasma APN levels may improve endothelial function, and reduce cardiovascular complications suffered by diabetic patients. §Address proofs to:
To assess the compliance of treatment, its affecting factors, and reasons for dropout, a questionnaire was mailed to a cohort of 2139 subjects who received sildenafil prescriptions for erectile dysfunction (ED) at our institution from 1999 to 2002. A total of 726 subjects (34%) with a mean age of 67 years answered the questionnaires. The response rate for sildenafil treatment was 67%. Of these sildenafil responders, 43% reported that they continued using sildenafil while 57% did not, in a mean follow-up of 3 years. Common reasons for discontinuation were effect below expectations, high cost, loss of interest in sex, and inconvenience in obtaining sildenafil. The continuers showed a higher rate than the discontinuers (P < 0.05) of having tried other treatments, dose titration, and a dose higher than 50 mg. The discontinuers reported having a lower mean responding dose and improvement score post sildenafil treatment than the continuers. In conclusion, effect below expectations was the leading reason for discontinuation of sildenafil treatment. How ED subjects tried the medication and the adequacy of education in the initial treatment period may impact the compliance of sildenafil treatment.
Thrombosis and its complications are the leading cause of death in patients with diabetes. Metformin, a first-line therapy for type 2 diabetes, is the only drug demonstrated to reduce cardiovascular complications in diabetic patients. However, whether metformin can effectively prevent thrombosis and its potential mechanism of action is unknown. Here we show, metformin prevents both venous and arterial thrombosis with no significant prolonged bleeding time by inhibiting platelet activation and extracellular mitochondrial DNA (mtDNA) release. Specifically, metformin inhibits mitochondrial complex I and thereby protects mitochondrial function, reduces activated platelet-induced mitochondrial hyperpolarization, reactive oxygen species overload and associated membrane damage. In mitochondrial function assays designed to detect amounts of extracellular mtDNA, we found that metformin prevents mtDNA release. This study also demonstrated that mtDNA induces platelet activation through a DC-SIGN dependent pathway. Metformin exemplifies a promising new class of antiplatelet agents that are highly effective at inhibiting platelet activation by decreasing the release of free mtDNA, which induces platelet activation in a DC-SIGN-dependent manner. This study has established a novel therapeutic strategy and molecular target for thrombotic diseases, especially for thrombotic complications of diabetes mellitus.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.