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Diabetes has been related to changes in vascular responses, mainly an increase in the vasoconstrictor responses and a decrease in the vasodilator responses. The literature has now begun to study the effects of diabetes in the early stages of development; the first studies on these stages indicate that diabetes produces different changes compared to the advanced stages. For that reason, the aim of this work was to evaluate the responses to norepinephrine and dopamine on normotensive and hypertensive rats with 4 weeks of diabetes evolution. The results showed that 4 weeks of diabetes produces a decrease of the vasopressor response to both agents (norepinephrine and dopamine). These results suggest that in the early stages, there are changes that help to decrease the pressor responses and these changes could disappear in the advanced stages. [ABSTRACT FROM AUTHOR]

Endothelial dysfunction plays an important role in the pathogenesis of hypertension. Other risk factors of atherosclerosis also affect its development. The aim of the study was to assess nitric oxide metabolites concentration (nitrites and nitrates Nox) and endothelin (ET-1) in plasma and cyclic 3,5-guanosine monophosphate (cGMP) in 24 h-urine collection in patients with noncomplicated hypertension without risk factors of atherosclerosis and in hypertensive patients with coronary artery disease (CAD). Sixty-eight subjects were included in the study (44 men, 24 women), aged 47 ± 76 years, allotted into four groups: I - controls (18 clinically healthy subjects); II - 12 subjects with hypertension without risk factors of atherosclerosis; III - 16 subjects with hypertension and risk factors of atherosclerosis; and IV - 22 subjects with hypertension and CAD. Plasma NOx concentration was determined using the Greiss method, plasma ET-1 by ELISA, and urine cGMP using the immunoenzymatic method. Plasma NOx concentration was 14.00 ± 6.88 μmol/L in group I, in group II - 18.62 ± 5.84 μmol, in group III - 9.96 ± 4.72 μmol/L, and in group IV - 8.78 ± 3.72 μmol/L. Statistically significant differences were between groups I and III (p < 0.05) and I and IV (p < 0.04) and groups II and III (p < 0.01) and II and IV (p < 0.01). The concentration of cGMP in 24 h urine collection was in group I - 40 ± 24 pmol/L; in group II - 54 ± 41 pmol/L; in group III - 38 ± 32 pmol/L; and in group IV - 42 ± 36 pmol/L. There were no significant differences between the groups. Plasma ET-1 concentration was 3.86 ± 0.52 pg/mL in group I, in group II - 4.05 ± 0.71 pg/mL, in group III - 4.22 ± 0.79 pg/mL and in group IV - 4.38 ± 0.75 pg/mL. Statistically significant differences were between group I and III (p < 0.05), I and IV (p < 0.03), and between group II and IV (p < 0.04). Endothelial dysfunction was not found in hypertensive patients without a family history of cardiovascular diseases and without other risk factors of atherosclerosis. Deterioration of endothelial function was observed in patients with hypertension with risk factors of atherosclerosis. It was most pronounced in those with CAD. [ABSTRACT FROM AUTHOR]

Diabetes mellitus has assumed epidemic proportions in most parts of the world, and it is a major source of morbidity in developed countries. In addition, in several instances, diabetes is associated with a variety of metabolic abnormalities, including abdominal obesity, insulin resistance, hypertension, dyslipidemia, and hyperglycemia. There is considerable evidence that hyperglycemia causes the generation of reactive oxygen species (ROS), ultimately leading to increased oxidative stress in a variety of tissues. In the absence of an appropriate compensatory response by the endogenous antioxidants, such as vitamins C and E, catalase, glutathione, and superoxide dismutase, oxidative stress dominates, resulting in the activation of stress-sensitive intracellular signaling pathways. One of the major consequences is the generation of gene products that cause cellular damage and are ultimately responsible for the late complications of diabetes. The ability of antioxidants to protect against the effects of hyperglycemia in vitro, along with the clinical benefits often reported following antioxidant therapy, supports a causative role of oxidative stress in mediating and/or worsening these abnormalities. This review will focus on the critical assessment of the literature as it relates to the association between oxidative stress and diabetes, followed by the role of oxidative stress in the complications of type 2 diabetes mellitus. Finally, a review of the use of the antioxidant vitamin E will be provided in diabetic patients by assessing and evaluating some of the clinical trials in the literature. [ABSTRACT FROM AUTHOR]

In essential hypertension (EH) patients, blood pressure can modify serum concentrations of some soluble forms of cell adhesion molecules (CAM), e.g., soluble E-selectin (sE-selectin) and soluble vascular cell adhesion molecule-1 (sVCAM-1). The objective of this study was to compare the serum levels of these CAMs in compensated (CH) and non-compensated (NCH) EH patients. Our findings show that sE-selectin and sVCAM-1 levels are higher in EH patients than normotensive subjects (sVCAM-1: 796 ± 52 vs. 605 ± 24 ng/mL, p < 0.0001, and sE-selectin: 71 ± 21 vs. 48 ± 14 ng/mL, p < 0.0001). Serum concentrations of both CAMs was higher in NCH patients than CH patients. High arterial blood pressure (ABP) may therefore increase the production of cell adhesion molecules, probably through endothelial activation. [ABSTRACT FROM AUTHOR]

Hypertension and obesity are risk factors for coronary heart diseases in adults. In turn, childhood overweight and high blood pressure increase the risk of subsequent obesity and hypertension in adulthood. Human obesity is characterized by profound alterations of hemodynamic and metabolic states. Whether these alterations involve sympathetic nervous system control on cardiac function is controversial. We report the results of our study, conducted in a sample of obese adolescents by using power spectral analysis of heart rate variability. An increase in sympathetic tone coupled with a reduction in vagal tone was found. This allowed us to hypothesize that autonomic nervous system changes depend on the time course of obesity development. It is still unclear if treatment of obesity in adolescence prevents subsequent autonomic imbalance and hypertension. [ABSTRACT FROM AUTHOR]