scholarly journals Endothelial Dysfunction: Is There a Hyperglycemia-Induced Imbalance of NOX and NOS?

2019 ◽  
Vol 20 (15) ◽  
pp. 3775 ◽  
Author(s):  
Cesar A. Meza ◽  
Justin D. La Favor ◽  
Do-Houn Kim ◽  
Robert C. Hickner

NADPH oxidases (NOX) are enzyme complexes that have received much attention as key molecules in the development of vascular dysfunction. NOX have the primary function of generating reactive oxygen species (ROS), and are considered the main source of ROS production in endothelial cells. The endothelium is a thin monolayer that lines the inner surface of blood vessels, acting as a secretory organ to maintain homeostasis of blood flow. The enzymatic production of nitric oxide (NO) by endothelial NO synthase (eNOS) is critical in mediating endothelial function, and oxidative stress can cause dysregulation of eNOS and endothelial dysfunction. Insulin is a stimulus for increases in blood flow and endothelium-dependent vasodilation. However, cardiovascular disease and type 2 diabetes are characterized by poor control of the endothelial cell redox environment, with a shift toward overproduction of ROS by NOX. Studies in models of type 2 diabetes demonstrate that aberrant NOX activation contributes to uncoupling of eNOS and endothelial dysfunction. It is well-established that endothelial dysfunction precedes the onset of cardiovascular disease, therefore NOX are important molecular links between type 2 diabetes and vascular complications. The aim of the current review is to describe the normal, healthy physiological mechanisms involved in endothelial function, and highlight the central role of NOX in mediating endothelial dysfunction when glucose homeostasis is impaired.


2014 ◽  
Author(s):  
◽  
Leryn J. Boyle

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT AUTHOR'S REQUEST.] Individuals with type 2 diabetes (T2D) have blunted femoral artery insulin mediated blood flow which is critical for the delivery and uptake of glucose into skeletal muscle. However, it is unclear in humans the precise mechanisms by which insulin resistance impairs insulin stimulated blood flow. Further, chronic physical inactivity is a powerful stimulus for reduced insulin sensitivity and vascular dysfunction; however, the effects of short term, modest reductions in physical activity are limited. Thus, we examined 1) if inactivity for 5 days would impair endothelial function in healthy individuals (study one) 2) if reducing whole body insulin sensitivity, via 5 days of inactivity, would impair the blood flow response to insulin stimulation in parallel with glycemic control (study two) and 3) phosphorylation of endothelial nitric oxide (eNOS) and endothelin-1 (ET-1) production to insulin stimulation would be decreased and increased, respectively, in insulin resistant individuals (study three). We demonstrated significant reductions in endothelial function with only 5 days of reduced daily steps while blood flow to glucose ingestion was unaltered. Further, in obese humans with type 2 diabetes it does not appear that that the reduction in blood flow to 1 hr of insulin stimulation is due to altered peNOS or ET-1. Collectively, these data suggest that reduced daily physical activity and chronic insulin resistance mediate negative impacts on vascular function and insulin stimulated blood flow and signaling.



2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Ana Paula Villela Dantas ◽  
Zuleica Bruno Fortes ◽  
Maria Helena Catelli de Carvalho

Gender plays a pivotal role in the onset as well as in the progression of the cardiovascular disease with a higher morbidity and mortality being detected in men with respect to women. Type 2 Diabetes Mellitus (T2DM) may reduce gender-related differences in the prevalence of cardiovascular disease by fading the vascular protective effects afforded by estrogen in females. This article will discuss the role of sex and sex hormones on the incidence and mechanisms involved in vascular dysfunction associated to T2DM, which might explain why women with T2DM lack the vascular protection.



Author(s):  
Nermien Abd El Rahman Ibraheim ◽  
Fatema El Zahraa Sayed Bukhary ◽  
Yehia Zakareia Mahmoud ◽  
Mahmoud Ragab Mohamed ◽  
Salama Rabei Abdel-Rahim


2008 ◽  
Vol 10 (3) ◽  
pp. 198-211 ◽  
Author(s):  
Vivienne A. Ezzat ◽  
Edward R. Duncan ◽  
Stephen B. Wheatcroft ◽  
Mark T. Kearney


2012 ◽  
Vol 02 (03) ◽  
pp. 338-345 ◽  
Author(s):  
Kazunari Suzuki ◽  
Kentaro Watanabe ◽  
Tatsuya Suzuki ◽  
Motoshi Ouchi ◽  
Shoko Futami-Suda ◽  
...  


2021 ◽  
pp. 43-47
Author(s):  
Liliia Mogylnytska

Cardiovascular disease is the leading cause of death in diabetes mellitus. Endothelial dysfunction is the first step in the development of atherosclerotic vascular lesions, which underlies cardiovascular pathology, and adhesion molecules secreted by the endothelium during inflammatory changes are involved in the progression of this lesion. The objective: the serum level of adhesive molecules (ІCAM-1, VCAM-1, Е-selectin) in hypertensive and non-hypertensive type 2 diabetes patients as a marker of endothelial dysfunction and its relationship with other risk factors for cardiovascular disease was studied. Materials and methods. We examined 64 patients with type 2 diabetes, which were divided into two subgroups: the first subgroup – 41 hypertensive type 2 diabetes patients (age – 53,56±7,14 years, BMI – 32,2±87,4; HbA1c – 9,97±2,02%), the second subgroup – 23 nonhypertensive type 2 diabetes patients (age – 50,5±4,92 years, BMI – 25,4±5,22; HbA1c – 9,09±1,95%). The control group included 18 people without diabetes with normal blood pressure (age – 50,72±6,98 years, BMI – 24,71±4,88; HbA1c – 5,26±0,42%). The serum level was determined by immunoenzyme assay. The significance of the difference between the mean values was determined by the t-Student test. Multifactor regression analysis was used to assess the relationships between the studied factors. Results. We revealed an increase of serum levels of ІCAM-1, VCAM-1, Е-selectin in hypertensive (+71,62%, +68,42%, +66,95%, respectively) and non-hypertensive type 2 diabetes patients (+46,17%, +62,79%, +42,85%, respectively) compared with the control group (p<0,01). The serum concentration of ІCAM-1, Е-selectin was higher in hypertensive type 2 diabetes patients compared to non-hypertensive type 2 diabetes patients (+17,27%, +16,86%, respectively, p<0,01). There was a significant effect of Hb1Ac, lipids, insulin resistance on the serum level of ІCAM-1, VCAM-1, Е-selectin (p<0,01). The corresponding regression equations are derived. Conclusion. There is an increase of serum level of ІCAM-1, VCAM-1, Е-selectin in hypertensive and non-hypertensive type 2 diabetes patients, which indicates the development of endothelial dysfunction. Hypertension, hyperglycemia, dyslipidemia and insulin resistance contribute to the development of these changes.



Diabetes Care ◽  
2019 ◽  
Vol 42 (10) ◽  
pp. e159-e161 ◽  
Author(s):  
Atsushi Tanaka ◽  
Michio Shimabukuro ◽  
Noritaka Machii ◽  
Hiroki Teragawa ◽  
Yosuke Okada ◽  
...  


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Ahmad Khusairi Azemi ◽  
Siti Safiah Mokhtar ◽  
Aida Hanum Ghulam Rasool

Diabetes mellitus is associated with endothelial dysfunction; it causes progressive vascular damage resulting from an impaired endothelium-dependent vasorelaxation. In the diabetes state, presence of hyperglycemia and insulin resistance predisposes to endothelial dysfunction. Clinacanthus nutans, widely used as a traditional medicine for diabetes is reported to have hypoglycemic, hypolipidemic, antioxidant, and anti-inflammatory properties. However, the possibility of C. nutans affecting the vascular endothelial function in diabetes remains unclear. This study was aimed at evaluating the effects of C. nutans methanolic leaves extract (CNME) on endothelial function in a type 2 diabetes (T2DM) rat model. Sixty male Sprague-Dawley rats were divided into five groups (n=12 per group): nondiabetic control, nondiabetic treated with four weeks of CNME (500 mg/kg/daily), untreated diabetic rats, diabetic treated with metformin (300 mg/kg/daily), and diabetic treated with CNME (500 mg/kg/daily). T2DM was induced by a single intraperitoneal injection of low-dose streptozotocin (STZ) to rats fed with high-fat diet (HFD). Endothelial-dependent and endothelial-independent relaxations and contractions of the thoracic aorta were determined using the organ bath. Aortic endothelial nitric oxide synthase (eNOS) expression was determined using Western blotting. Endothelial-dependent relaxation was reduced in diabetic rats. Both diabetic groups treated with CNME or metformin significantly improved the impairment in endothelium-dependent vasorelaxation; this was associated with increased expression of aortic eNOS protein. CNME- and metformin-treated groups also reduced aortic endothelium-dependent and aortic endothelium-independent contractions in diabetics. Both of these diabetic-treated groups also reduced blood glucose levels and increased body weight compared to the untreated diabetic group. In conclusion, C. nutans improves endothelial-dependent vasodilatation and reduces endothelial-dependent contraction, thus ameliorating endothelial dysfunction in diabetic rats. This may occur due to its effect on increasing eNOS protein expression.



2000 ◽  
Vol 71 (3) ◽  
pp. 725-732 ◽  
Author(s):  
Christine H Lindquist ◽  
Barbara A Gower ◽  
Michael I Goran


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