Endothelial Nitric Oxide Increase Research Articles

Relationship between Skin Temperature Variation and Muscle Damage Markers after a Marathon Performed in a Hot Environmental Condition.

This study aimed to assess the effect of a marathon running at a hot environmental temperature on the baseline skin temperature (Tsk) of the posterior day and to analyze the relationship between Tsk response and muscle damage markers variation. The Tsk, creatine kinase, and lactate dehydrogenase of 16 marathon runners were assessed four times before (15 days and 45 min) and after (24 h and 6 days) a marathon in a hot environment (thermal stress index = 28.3 ± 3.3 °C and humidity ~81%). The Tsk of thirteen different body regions of both right and left lower limbs were analyzed. Higher values after the marathon were observed than 45 min before in creatine kinase (174.3 ± 136.4 UI/L < 1159.7 ± 699.7 UI/L, p < 0.01 and large effect size) and lactate dehydrogenase (362.6 ± 99.9 UI/L < 438 ± 115.5 UI/L, p = 0.02 and moderate effect size). Generally, Tsk was higher the day after the marathon than at the other three moments (e.g., rectus femoris region, 6 days before vs. the day after, 95% confidence interval of the difference (0.3, 1.6 °C), p = 0.04 and large effect size). No relationship or correlation was observed between the variation of Tsk and muscle damage markers (p > 0.05). In conclusion, performing a marathon in a hot environmental condition results in a higher Tsk the day after the marathon. This increase in Tsk could be because of the heat generated by the marathon and its subsequent physiological processes (e.g., increase in endothelial nitric oxide, glycogen resynthesis, or increase of systemic hormones), which would be reflected in the Tsk due to the peripheral vasodilation promoted by the hot environment. However, among these processes, muscle damage does not seem to be of great importance due to the lack of an observed relationship between Tsk and muscle damage markers.

Update of the European Society of Hypertension document on arterial hypertension and erectile dysfunction 2020

Hypertension has long ceased to be a disease exclusively of the elderly, now more and more often it affects young and middle-aged people. Therefore, the prescribed treatment should take into account all possible complications during therapy. This is especially true for antihypertensive treatment in men, as there is evidence of adverse effects of some groups of drugs for the treatment of hypertension on erectile function. This leads to a significant reduction in the quality of life and the patient’s commitment to treatment. Nebivolol has vasodilating properties and promotes the release of nitric oxide and its bioavailability. It has been experimentally proven that nebivolol, leading to an increase in endothelial nitric oxide, is able to promote endothelium-dependent relaxation of the corpora cavernosa of the penis. Such positive effects have not been demonstrated in studies with other beta-blockers (metoprolol, atenolol), which makes it the drug of choice in young/middle-aged patients, as it not only does not have a negative effect on sexual function, but also can improve it.

Nanoliposomal Nitroglycerin Exerts Potent Anti-Inflammatory Effects.

Nitroglycerin (NTG) markedly enhances nitric oxide (NO) bioavailability. However, its ability to mimic the anti-inflammatory properties of NO remains unknown. Here, we examined whether NTG can suppress endothelial cell (EC) activation during inflammation and developed NTG nanoformulation to simultaneously amplify its anti-inflammatory effects and ameliorate adverse effects associated with high-dose NTG administration. Our findings reveal that NTG significantly inhibits human U937 cell adhesion to NO-deficient human microvascular ECs in vitro through an increase in endothelial NO and decrease in endothelial ICAM-1 clustering, as determined by NO analyzer, microfluorimetry, and immunofluorescence staining. Nanoliposomal NTG (NTG-NL) was formulated by encapsulating NTG within unilamellar lipid vesicles (DPhPC, POPC, Cholesterol, DHPE-Texas Red at molar ratio of 6:2:2:0.2) that were ~155 nm in diameter and readily uptaken by ECs, as determined by dynamic light scattering and quantitative fluorescence microscopy, respectively. More importantly, NTG-NL produced a 70-fold increase in NTG therapeutic efficacy when compared with free NTG while preventing excessive mitochondrial superoxide production associated with high NTG doses. Thus, these findings, which are the first to reveal the superior therapeutic effects of an NTG nanoformulation, provide the rationale for their detailed investigation for potentially superior vascular normalization therapies.

Abstract 14296: Site-targeting Nitroglycerin Nanotherapeutic for Local Immunosuppression Without Induction of Tolerance

Nitroglycerin (NTG) markedly enhances nitric oxide (NO) bioavailability. However, its ability to mimic the anti-inflammatory properties of NO remains unknown. Here, we examined whether NTG can suppress endothelial cell (EC) activation during inflammation and developed NTG nanoformulation to simultaneously amplify its anti-inflammatory effects and ameliorate adverse effects associated with high-dose NTG administration. Our findings reveal that NTG significantly inhibits human monocyte adhesion to NO-deficient human microvascular ECs in vitro (EC50 = 0.64 uM) through an increase in endothelial NO and decrease in endothelial ICAM-1 clustering, as determined by NO analyzer, microfluorimetry, and immunofluorescence staining. Nanoliposomal NTG (NTG-NL) was formulated by encapsulating NTG within unilamelar lipid nanoparticles that were ~150 nm in diameter and readily uptaken by ECs, as determined by dynamic light scattering and quantitative fluorescence microscopy, respectively. More importantly, NTG-NL produced an approximately two orders of magnitude greater anti-inflammatory effect than free NTG while preventing excessive mitochondrial superoxide production and loss of arterial vasorelaxation associated with high NTG doses. Finally, to facilitate targeting of NTG-NL to inflamed ICAM-1-expressing vessels, we have tethered a non-immunogenic fragment of ICAM-1 antibody to the surface of NTG-NL. Our preliminary in vitro studies show that NTG-NL modified with anti-ICAM-1 fragment exhibits 6-fold greater binding to inflamed (ICAM-1-expressing) ECs than to normal ECs. Thus, by identifying the superior therapeutic effects of NTG nanoformulation and conferring potent site-targeting capability to it, this study provides the rationale for detailed investigation of NTG nanotherapeutic as a potentially superior anti-inflammatory therapy.

Effects of exercise training on stress-induced vascular reactivity alterations: role of nitric oxide and prostanoids.

Background:Physical exercise may modify biologic stress responses. Objective:To investigate the impact of exercise training on vascular alterations induced by acute stress, focusing on nitric oxide and cyclooxygenase pathways. Method:Wistar rats were separated into: sedentary, trained (60-min swimming, 5 days/week during 8 weeks, carrying a 5% body-weight load), stressed (2 h-immobilization), and trained/stressed. Response curves for noradrenaline, in the absence and presence of L-NAME or indomethacin, were obtained in intact and denuded aortas (n=7-10). Results:None of the procedures altered the denuded aorta reactivity. Intact aortas from stressed, trained, and trained/stressed rats showed similar reduction in noradrenaline maximal responses (sedentary 3.54±0.15, stressed 2.80±0.10*, trained 2.82±0.11*, trained/stressed 2.97± 0.21*, *P<0.05 relate to sedentary). Endothelium removal and L-NAME abolished this hyporeactivity in all experimental groups, except in trained/stressed rats that showed a partial aorta reactivity recovery in L-NAME presence (L-NAME: sedentary 5.23±0,26#, stressed 5.55±0.38#, trained 5.28±0.30#, trained/stressed 4.42±0.41, #P<0.05 related to trained/stressed). Indomethacin determined a decrease in sensitivity (EC50) in intact aortas of trained rats without abolishing the aortal hyporeactivity in trained, stressed, and trained/stressed rats. Conclusions:Exercise-induced vascular adaptive response involved an increase in endothelial vasodilator prostaglandins and nitric oxide. Stress-induced vascular adaptive response involved an increase in endothelial nitric oxide. Beside the involvement of the endothelial nitric oxide pathway, the vascular response of trained/stressed rats involved an additional mechanism yet to be elucidated. These findings advance on the understanding of the vascular processes after exercise and stress alone and in combination.

Folic acid enlarges the armamentarium for the treatment of coronary vasospasm

Qipshidze et al. (2010) described in the Journal of Cell Physiology that folic acid ameliorates acetylcholine-induced vasoconstriction in hyperhomocysteinemic cystathionine beta synthase heterozygote (CBS /þ) mice, and that this effect can be explained by an increase in endothelial nitric oxide (eNOS) expression and nitric oxide (NO) bioavailability in the coronary artery. The authors have investigated the role of eNOS in acetylcholine-induced vasoconstriction in CBS /þ mice by measuring total protein (by immunolabelling) and mRNA levels (by RT-PCR). However, they did not perform eNOS uncoupling assessment, which is of essential importance to evaluate the active or inactive state of eNOS. Qipshidze et al. (2010) assessed only the NO-pathway using diaminofluorescein-2-diacetat staining. However, it should be considered that compartmentalization of diaminofluorescein-2 around elastic fibers limits its potential to characterize the site of NO production at the subcellular level. Further, reaction of diaminofluorescein-2 with reagents commonly used in NO research, such as ferricyanide, N-ethylmaleimide, and tempol, may also interfere with diaminofluorescein-2 fluorescence that can be misinterpreted as NO signals. Importantly, in cell-free systems, the diaminofluorescein-2 dependent signal is enhanced in the presence of superoxide, suggesting that diaminofluorescein-2 is indeed more sensitive to the degradation product of NO, peroxynitrite, rather than to NO itself (Roychowdhury et al., 2002). This would imply that the detection of higher signals in the presence of diaminofluorescein-2 do not necessarily indicate higher levels of bioavailable NO but can rather indicate the reverse, higher levels of peroxynitrite and NO scavenging. In any case, even if diaminofluorescein-2 were specific for NO or more sensitive for NO than for peroxynitrite, higher steady state levels of NO must not necessarily indicate an effect of eNOS and higher production of NO but can also indicate reduced oxidative stress or a direct anti-oxidant effect of folate. Thus, the demonstration of recoupling of eNOS from its monomeric to its dimeric state would have been essential to justify the authors’ conclusion. In addition, UV illumination can lead to formation of high levels of nitrosating species that interferewith NO detection coming from enzymatic sources (Rodriguez et al., 2005). Therefore, assessment of NO alone by diaminofluorescein-2-diacetate cannot conclude whether or not this molecule is generated by eNOS. Other methods, such as eNOSmonomer/dimer blot, dichlorofluorescin staining, and NOS-dependent ROS production using lucigenin-enhanced chemiluminescence should also be considered. Unfortunately, the authors also did not investigate the role of folic acid-induced changes in high-energy phosphate metabolism. It has been described that folic acid, besides its well-known homocysteine-lowering and antioxidant effect, preserves the high-energy phosphate metabolism during myocardial ischemia with subsequent less myocardial necrosis, better myocardial function, and less arrhythmias (Moens et al., 2008). Title et al. (2000) have demonstrated that endothelial function, as assessed by flow-mediated dilation (FMD) in patients with coronary artery diseases, is ameliorated by reducing the level of plasma homocysteine. This is in contrast with a study ofDoshi et al. (2001), which showed no correlation between FMD improvement and plasma homocysteine level in patients with coronary artery diseases. This result is supported by Moens et al. (2007) demonstrating in patients with acute myocardial infarction that the beneficial effect of folic acid on endothelial dysfunction is independent of baseline homocysteine-level. Chambers et al. (2000) have shown that improved FMD correlates with the reduction in free (unbound)-reduced homocysteine in patients with coronary heart diseases. Unfortunately, Qipshidze et al. (2010) did not assess any of the different forms (reduced, mixed disulphides, and total) of homocysteine. It has been described that smoothmuscle constriction of the coronary artery, the so-called coronary vasospasm, is associated with increased markers of oxidative stress (Motoyama et al., 1998) and inflammation (Li et al., 2008). Interestingly, certain behavioral traits including type A personality, panic disorder, and severe anxiety, have been described to be associated with coronary artery vasospasm (Rasmussen et al., 1986; Vidovich et al., 2009). However, no data are available regarding whether these clinical situations are associated with changes in endothelial NOS. Translation of these pre-clinical data to humans, and especially to patientswith these behavioral conditions is therefore well encouraged. The data provided in the paper of Qipshidze et al. (2010) are intriguing since they open theraupetic possibilities for patient with coronary vasospasms. Nitrates and calcium channel

Modern views on amlodipine and new S-amlodipine medications

The review presents the latest evidence on the calcium antagonist amlodipine, summarizing its mechanisms of action, its pleiotropic, endothelial function-related effects, and its anti-atherogenic activity. Amlodipine suppresses the proliferation of vascular smooth myocytes and extracellular matrix and improves endothelial vasodilatation, despite the absence of L-type calcium channels in these cells. This mechanism is related to an increase in endothelial nitric oxide (NO) release. The results of experimental studies on the role of S and R amlodipine isomers in its hemodynamic and pleiotropic activity are presented. While S-amlodipine is a pharmacologically active blocker of L-type calcium channels, R-amlodipine increases endothelial NO release. New medications have been developed, based on S-amlodipine. It has been shown that S-amlodipine 5 mg/d is bioequivalent to amlodipine 10 mg/d. The pharmacodynamics analysis demonstrated that S-amlodipine 5 mg/d and amlodipine 10 mg/d did not differ significantly in terms of mean levels of systolic and diastolic blood pressure, or mean heart rate. S-amlodipine was better tolerated and characterised by a lower incidence of peripheral edema than amlodipine. However, the effects of S-amlodipine on hard end-points should be investigated in the long-term prospective studies.

Vascular oxidative stress increases dendritic cell adhesion and transmigration induced by homocysteine

Atherosclerosis is a long-term chronic inflammatory and immunological disease. Endothelial dysfunction and the dendritic cell (DC) immune response are pivotal early events in atherogenesis. This study investigated the effects and possible mechanisms of action of homocysteine (Hcy) on DC adhesion to and transmigration between endothelial cells (ECs), and indicated a novel immunoregulatory mechanism by which Hcy induces atherogenesis. When ECs were stimulated with increasing concentrations of Hcy, immunofluorescence showed that endothelial reactive oxygen species (ROS) generation strikingly increased, while nitrite assay showed that nitric oxide (NO) release markedly decreased. Furthermore, DC adhesion and transmigration were significantly increased when ECs were activated by Hcy. However, pretreatment of ECs with antioxidant before Hcy markedly attenuated the induction of DC adhesion and transmigration, dependent on the intracellular ROS decrease and endothelial NO increase. In conclusion, DC adhesion and transmigration are significantly increased by vascular oxidative stress under conditions of elevated Hcy levels. These findings provide insight into the inflammatory processes and immune responses occurring in atherosclerosis induced by Hcy.

SIRT1 promotes endothelium-dependent vascular relaxation by activating endothelial nitric oxide synthase

Reduced caloric intake decreases arterial blood pressure in healthy individuals and improves endothelium-dependent vasodilation in obese and overweight individuals. The SIRT1 protein deacetylase mediates many of the effects of calorie restriction (CR) on organismal lifespan and metabolic pathways. However, the role of SIRT1 in regulating endothelium-dependent vasomotor tone is not known. Here we show that SIRT1 promotes endothelium-dependent vasodilation by targeting endothelial nitric oxide synthase (eNOS) for deacetylation. SIRT1 and eNOS colocalize and coprecipitate in endothelial cells, and SIRT1 deacetylates eNOS, stimulating eNOS activity and increasing endothelial nitric oxide (NO). SIRT1-induced increase in endothelial NO is mediated through lysines 496 and 506 in the calmodulin-binding domain of eNOS. Inhibition of SIRT1 in the endothelium of arteries inhibits endothelium-dependent vasodilation and decreases bioavailable NO. Finally, CR of mice leads to deacetylation of eNOS. Our results demonstrate that SIRT1 plays a fundamental role in regulating endothelial NO and endothelium-dependent vascular tone by deacetylating eNOS. Furthermore, our results provide a possible molecular mechanism connecting the effects of CR on the endothelium and vascular tone to SIRT1-mediated deacetylation of eNOS.

Netrin-1 induces angiogenesis via a DCC-dependent ERK1/2-eNOS feed-forward mechanism

Netrin-1 is critical for axonal pathfinding which shares similarities with formation of vascular network. Here we report that netrin-1 induction of angiogenesis is mediated by an increase in endothelial nitric oxide (NO*) production, which occurs via a DCC-dependent, ERK1/2-eNOS feed-forward mechanism. Exposure of mature aortic endothelial cells to netrin-1 resulted in a potent, dose-dependent increase in NO* production, detected by electron spin resonance. Scavenging NO* with 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (PTIO) abolished netrin-1 stimulated angiogenesis. Netrin-1-stimulated NO* production or angiogenesis was inhibited by DCC antibody, DCC small interfering RNA (siRNA), specific inhibitors (PD98059, U0126), or siRNAs for MEK1/2. PTIO attenuated ERK1/2 phosphorylation, indicating a feed-forward mechanism. Netrin-1 induced a time-dependent phosphorylation of eNOS(s1179, s116) and a rapid dephosphorylation of eNOS(t497). Only eNOS(s1179) was sensitive to U0126 or PTIO. These data characterized a mechanism whereby netrin-1 promotes angiogenesis, which may broadly relate to cardiovascular, neuronal and cancer physiology.

4P-1062 Rapid increasein endothelial nitric oxide production by bradykinin is mediated by protein kinase A signaling pathway

4P-1062 Rapid increasein endothelial nitric oxide production by bradykinin is mediated by protein kinase A signaling pathway