dimethylarginine and Erectile-Dysfunction

Erectile Dysfunction (ED) is one of the main complaints of aging male. A reduced production of Nitric Oxide (NO) may be involved in ED pathogenesis. NO is synthesized from l-Arginine, and asymmetrical dimethylarginine inhibits all NO synthases. DDAH1 and DDAH2 are genes that encode enzymes responsible for metabolizing ADMA. We aimed to assess whether: 1) ADMA and nitrite levels associated with ED risk and with symptoms intensity; and whether 2) DDAH1 and DDAH2 gene polymorphisms associate with changes in biochemical data, and with ED risk and symptoms intensity. In this study were included 98 healthy controls and 130 ED patients. ADMA levels were measured by ELISA and nitrite levels by Chemiluminescence. DDAH1 and DDAH2 polymorphisms were assessed by Taqman assays. We found that ED had increased nitrite levels and lower ADMA levels than Control group (P < 0.05). We found a significant correlation of ADMA with Nitrite levels only in ED (B = -0.57, P < 0.001). Genotypes and haplotypes of DDAH1 were associated with ADMA levels in ED (P < 0.05), while haplotypes of DDAH2 were associated with levels of nitrite in ED (P < 0.05). Erectile dysfunction patients show an association between DDAH1 and DDAH2 polymorphisms with ADMA levels, which in turn are negatively correlated with nitrite levels. This is not evident on healthy controls.

Topics: Adult; Aged; Aged, 80 and over; Amidohydrolases; Arginine; Erectile Dysfunction; Female; Humans; Male; Middle Aged; Nitric Oxide; Polymorphism, Genetic

Type 2 diabetes mellitus (T2DM) has become a major public health issue and is considered a risk factor for erectile dysfunction (ED). T2DM is also associated with androgen deficiency. However, there have been few basic studies on androgen replacement therapy (ART) for ED treatment in T2DM animal models, and the mechanism underlying the effect of ART on T2DM-induced ED is unclear.. To investigate the effect of ART on ED in T2DM rats by examining inflammatory and nitric oxide (NO)-related factors.. Otsuka Long-Evans Tokushima Fatty (OLETF) rats and their controls, Long-Evans Tokushima Otsuka (LETO) rats, were distributed into three groups: LETO, OLETF, and ART. In the ART group, OLETF rats were treated daily with testosterone (3 mg/kg/day, subcutaneously) from 20 to 25 weeks of age; LETO and OLETF rats received vehicle only.. We measured erectile function by using measurements of the ratio between intracavernosal pressure (ICP) and mean arterial pressure (MAP) following electrical stimulation of the cavernous nerve and by evaluating the endothelial function of the corpus cavernosum in an isometric tension study. Expression of endothelial NO synthase (eNOS), inducible NO synthase (iNOS), sirtuin-1 (Sirt1), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-α) mRNA was detected using polymerase chain reaction.. The ICP/MAP ratio in the OLETF group was significantly decreased and that in the ART group was significantly improved (P < 0.01). The response to acetylcholine was significantly decreased in the OLETF group and improved in the ART group (P < 0.01). Although expression of eNOS and Sirt1 mRNA was decreased and that of iNOS, IL-6, and TNF-α mRNA was increased in the OLETF group, ART improved mRNA expression.. ART suppressed inflammation in rats with T2DM and metabolic disorders and improved their endothelial and erectile functions. ART could be effective for T2DM-induced ED and may be considered a potential ED treatment method.

Topics: Androgens; Animals; Arginine; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 2; Electric Stimulation; Erectile Dysfunction; Hormone Replacement Therapy; Interleukin-6; Male; Nitric Oxide Synthase Type II; Nitric Oxide Synthase Type III; Penile Erection; Penis; Rats, Long-Evans; Testosterone; Tumor Necrosis Factor-alpha

Coronary endothelial dysfunction (CED) precedes atherosclerosis and is associated with cardiovascular events. Both CED and erectile dysfunction (ED) are partly mediated by impairment in the nitric oxide pathway. ED is associated with established coronary atherosclerosis, but its relationship with early coronary atherosclerosis and CED is unknown. This study was designed to test the hypothesis that CED is associated with ED in men with early coronary atherosclerosis. Moreover, the role of the nitric oxide synthase inhibitor asymmetric dimethylarginine (ADMA) was investigated; ADMA is a novel endogenous competitive inhibitor of nitric oxide synthase and has been shown to be an independent marker for cardiovascular disease.. Fifty-six men without obstructive coronary artery disease (CAD) who underwent coronary endothelial function testing were studied. ADMA levels were determined and all men were asked to complete the International Index of Erectile Function-5 questionnaire to assess erectile function. Patients were divided according to the presence (n = 32) or absence (n = 24) of CED. Men with CED had significant impairment of erectile function (P = 0.008) and significantly higher ADMA levels (0.50 +/- 0.06 vs. 0.45 +/- 0.07 ng/mL, P = 0.017) compared with men with normal endothelial function. Erectile function positively correlated with coronary endothelial function. This correlation was independent of age, body mass index, high-density lipoprotein, C-reactive protein, homeostasis model assessment of insulin resistance index, and smoking status.. CED is independently associated with ED and plasma ADMA concentration in men with early coronary atherosclerosis. This study further supports the role of the endothelium in systemic vascular diseases and the role of ADMA in the systemic manifestations of endothelial dysfunction.

Topics: Arginine; C-Reactive Protein; Coronary Artery Disease; Endothelium, Vascular; Erectile Dysfunction; Humans; Male; Middle Aged; Risk Factors

Coronary artery disease (CAD) and erectile dysfunction (ED) of vascular origin are closely related and share common risk factors. The endogenous NO synthase inhibitor asymmetrical dimethylarginine (ADMA) has recently been identified as an independent risk marker for cardiovascular disease and it was the purpose of the present study to investigate the role ADMA in ED with and without underlying CAD.. We determined plasma ADMA levels in 132 men with ED. Patients were divided into a group of 56 men with underlying CAD (ED-CAD) and a group of 76 men without clinical evidence for underlying CAD (ED-No-CAD). Diagnosis of ED was based on the International Index of Erectile Function Score (IIEF-5). Plasma ADMA concentrations in the ED-CAD group were elevated as compared to the ED-No-CAD group, median (IQR): 0.76 (0.65-0.91) micromol/l ADMA vs. 0.49 (0.36-0.71) micromol/l, p < 0.001. In a multiple logistic regression analysis adjusting for hypertension, hypercholesterolemia, low HDL cholesterol and diabetes or fasting glucose > or =6.1 mmol/l, ADMA remained a strong and independent predictor for presence of CAD. Odds ratios for second and third tertiles as compared to lowest tertile of plasma ADMA were 3.3 (95%CI, 1.1-10.3; p = 0.041) and 8.7 (95%CI, 2.8-27.2; p < 0.001), respectively.. As elevation of ADMA has been found to be associated with many risk factors for both CAD and ED, our data provide further strong evidence for the close interrelation of CAD and ED. Determination of ADMA may help to identify underlying cardiovascular disease in men with ED.

Topics: Age Distribution; Aged; Arginine; Biomarkers; Case-Control Studies; Comorbidity; Confidence Intervals; Coronary Artery Disease; Erectile Dysfunction; Humans; Logistic Models; Male; Middle Aged; Multivariate Analysis; Odds Ratio; Prevalence; Prognosis; Risk Assessment; Sensitivity and Specificity; Severity of Illness Index