scholarly journals New Modified Method for Determination of Nitric Oxide Synthase Activity in Plasma of Vitiligo Patients

2018 ◽  
Vol 34 (5) ◽  
pp. 2502-2509
Author(s):  
Jwan Abdulmohsin Zainulabdeen ◽  
Aymen Abdulsattar Al-kinani
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Healthy Individuals ◽  
Modified Method ◽  
Oxide Concentration ◽  
Nitric Oxide Concentration ◽  
And Gender ◽  
Oxide Synthase

Vitiligo is a non-contagious skin disorder that characterized by depigmentation of skin due to melanocyte impairment which may be caused to increase levels of free radicals (such as superoxide and nitric oxide) that causing an increase in oxidative stress. The purpose of this study was measured by the activity of oxide synthase (NOS) by our modified method and nitric oxide concentration in plasma of vitiligo patients. The activity of nitric oxide synthase was determined via a modified method by coupling two methods; the first method was based on converting L-arginine to L-citrulline and nitric oxide and the second was used to measure the concentration of nitric oxide. This modified method was applied to patients with vitiligo disease and healthy individuals who matched in age and gender with patients. The condition of this modified method was optimized and the results revealed the following: the activity of NOS was higher in a solution that contains: Tris buffer (50mM), arginine (100mM), calcium chloride (20mM), and NADPH (5mM) during 30 minutes, meanwhile the precision of this method was 2.03. In the current study, the results show that the levels of NOS activity and nitric oxide were affected by the disease in which both parameters appeared highly significant increases in vitiligo patients (p=0.000 and 0.002 respectively) in comparison with the healthy individuals. Results of the experiments proved that it is possible to depend on the modified method to measure the activity of nitric oxide synthase (NOS). Also, the increased levels of NOS activity and nitric oxide concentration in vitiligo patients support the autocytotoxic hypothesis which suggests that oxidative stress may have a role in melanocyte impairment.

Role of TLR-4/IL-6/TNF-α, COX-II and eNOS/iNOS pathways in the impact of carvedilol against hepatic ischemia reperfusion injury

2021 ◽  
pp. 096032712199944
Author(s):  
Mohamed IA Hassan ◽  
Fares EM Ali ◽  
Abdel-Gawad S Shalkami
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Nitric Oxide Synthase ◽  
Inducible Nitric Oxide Synthase ◽  
Liver Enzymes ◽  
Ischemia Reperfusion ◽  
Hepatic Ischemia ◽  
Hepatic Ischemia Reperfusion ◽  
Oxide Synthase ◽  
Inducible Nitric Oxide

Aim: Hepatic ischemia/reperfusion (I/R) injury is a syndrome involved in allograft dysfunction. This work aimed to elucidate carvedilol (CAR) role in hepatic I/R injury. Methods: Male rats were allocated to Sham group, CAR group, I/R group and CAR plus I/R group. Rats subjected to hepatic ischemia for 30 minutes then reperfused for 60 minutes. Oxidative stress markers, inflammatory cytokines and nitric oxide synthases were measured in hepatic tissues. Results: Hepatocyte injury following I/R was confirmed by a marked increase in liver enzymes. Also, hepatic I/R increased the contents of malondialdehyde however decreased glutathione contents and activities of antioxidant enzymes. Furthermore, hepatic I/R caused elevation of toll-like receptor-4 (TLR-4) expression and inflammatory mediators levels such as tumor necrosis factor-α, interleukin-6 and cyclooxygenase-II. Hepatic I/R caused down-regulation of endothelial nitric oxide synthase and upregulation of inducible nitric oxide synthase expressions. CAR treatment before hepatic I/R resulted in the restoration of liver enzymes. Administration of CAR caused a significant correction of oxidative stress and inflammation markers as well as modulates the expression of endothelial and inducible nitric oxide synthase. Conclusions: CAR protects liver from I/R injury through reduction of the oxidative stress and inflammation, and modulates endothelial and inducible nitric oxide synthase expressions.

scholarly journals Endothelial PPAR-γ provides vascular protection from IL-1β-induced oxidative stress

2016 ◽  
Vol 310 (1) ◽  
pp. H39-H48 ◽  
Author(s):  
Masashi Mukohda ◽  
Madeliene Stump ◽  
Pimonrat Ketsawatsomkron ◽  
Chunyan Hu ◽  
Frederick W. Quelle ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Endothelial Dysfunction ◽  
Nitric Oxide Synthase ◽  
Transgenic Mice ◽  
Stress Responses ◽  
Endothelial Nitric Oxide Synthase ◽  
Ppar Γ ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Loss of peroxisome proliferator-activated receptor (PPAR)-γ function in the vascular endothelium enhances atherosclerosis and NF-κB target gene expression in high-fat diet-fed apolipoprotein E-deficient mice. The mechanisms by which endothelial PPAR-γ regulates inflammatory responses and protects against atherosclerosis remain unclear. To assess functional interactions between PPAR-γ and inflammation, we used a model of IL-1β-induced aortic dysfunction in transgenic mice with endothelium-specific overexpression of either wild-type (E-WT) or dominant negative PPAR-γ (E-V290M). IL-1β dose dependently decreased IκB-α, increased phospho-p65, and increased luciferase activity in the aorta of NF-κB-LUC transgenic mice. IL-1β also dose dependently reduced endothelial-dependent relaxation by ACh. The loss of ACh responsiveness was partially improved by pretreatment of the vessels with the PPAR-γ agonist rosiglitazone or in E-WT. Conversely, IL-1β-induced endothelial dysfunction was worsened in the aorta from E-V290M mice. Although IL-1β increased the expression of NF-κB target genes, NF-κB p65 inhibitor did not alleviate endothelial dysfunction induced by IL-1β. Tempol, a SOD mimetic, partially restored ACh responsiveness in the IL-1β-treated aorta. Notably, tempol only modestly improved protection in the E-WT aorta but had an increased protective effect in the E-V290M aorta compared with the aorta from nontransgenic mice, suggesting that PPAR-γ-mediated protection involves antioxidant effects. IL-1β increased ROS and decreased the phospho-endothelial nitric oxide synthase (Ser1177)-to-endothelial nitric oxide synthase ratio in the nontransgenic aorta. These effects were completely abolished in the aorta with endothelial overexpression of WT PPAR-γ but were worsened in the aorta with E-V290M even in the absence of IL-1β. We conclude that PPAR-γ protects against IL-1β-mediated endothelial dysfunction through a reduction of oxidative stress responses but not by blunting IL-1β-mediated NF-κB activity.

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