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PloS One 2014Pharmacological inhibition of arginase and remote ischemic perconditioning (RIPerc) are known to protect the heart against ischemia/reperfusion (IR) injury.
BACKGROUND
Pharmacological inhibition of arginase and remote ischemic perconditioning (RIPerc) are known to protect the heart against ischemia/reperfusion (IR) injury.
PURPOSE
The objective of this study was to investigate whether (1) peroxynitrite-mediated RhoA/Rho associated kinase (ROCK) signaling pathway contributes to arginase upregulation following myocardial IR; (2) the inhibition of this pathway is involved as a cardioprotective mechanism of remote ischemic perconditioning and (3) the influence of diabetes on these mechanisms.
METHODS
Anesthetized rats were subjected to 30 min left coronary artery ligation followed by 2 h reperfusion and included in two protocols. In protocol 1 rats were randomized to 1) control IR, 2) RIPerc induced by bilateral femoral artery occlusion for 15 min during myocardial ischemia, 3) RIPerc and administration of the nitric oxide synthase inhibitor NG-monomethyl-L-arginine (L-NMMA), 4) administration of the ROCK inhibitor hydroxyfasudil or 5) the peroxynitrite decomposition catalyst FeTPPS. In protocol 2 non-diabetic and type 1 diabetic rats were randomosed to IR or RIPerc as described above.
RESULTS
Infarct size was significantly reduced in rats treated with FeTPPS, hydroxyfasudil and RIPerc compared to controls (P<0.001). FeTPPS attenuated both ROCK and arginase activity (P<0.001 vs. control). Similarly, RIPerc reduced arginase and ROCK activity, peroxynitrite formation and enhanced phospho-eNOS expression (P<0.05 vs. control). The cardioprotective effect of RIPerc was abolished by L-NMMA. The protective effect of RIPerc and its associated changes in arginase and ROCK activity were abolished in diabetes.
CONCLUSION
Arginase is activated by peroxynitrite/ROCK signaling cascade in myocardial IR. RIPerc protects against IR injury via a mechanism involving inhibition of this pathway and enhanced eNOS activation. The beneficial effect and associated molecular changes of RIPerc is abolished in type 1 diabetes.
Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Animals; Arginase; Diabetes Mellitus, Experimental; Enzyme Inhibitors; Ischemic Preconditioning; Male; Myocardial Reperfusion Injury; Peroxynitrous Acid; Rats; Rats, Sprague-Dawley; Signal Transduction; omega-N-Methylarginine; rho-Associated Kinases
PubMed: 25140754
DOI: 10.1371/journal.pone.0104731 -
Acta Medica Okayama 2015Lung hyperpermeability affects the development of acute respiratory distress syndrome (ARDS), but therapeutic strategies for the control of microvascular permeability... (Comparative Study)
Comparative Study
Inhibitory Effects of Edaravone, a Free Radical Scavenger, on Cytokine-induced Hyperpermeability of Human Pulmonary Microvascular Endothelial Cells:A Comparison with Dexamethasone and Nitric Oxide Synthase Inhibitor.
Lung hyperpermeability affects the development of acute respiratory distress syndrome (ARDS), but therapeutic strategies for the control of microvascular permeability have not been established. We examined the effects of edaravone, dexamethasone, and N-monomethyl-L-arginine (L-NMMA) on permeability changes in human pulmonary microvascular endothelial cells (PMVEC) under a hypercytokinemic state. Human PMVEC were seeded in a Boyden chamber. After monolayer confluence was achieved, the culture media were replaced respectively by culture media containing edaravone, dexamethasone, and L-NMMA. After 24-h incubation, the monolayer was stimulated with tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β). Fluorescein-labeled dextran was added. Then the trans-human PMVEC leak was measured. Expressions of vascular endothelial-cadherin (VE-cadherin) and zonula occludens-1 protein (ZO-1) were evaluated using real-time quantitative polymerase chain reaction and immunofluorescence microscopy. The results showed that TNF-α+IL-1β markedly increased pulmonary microvascular permeability. Pretreatment with edaravone, dexamethasone, or L-NMMA attenuated the hyperpermeability and inhibited the cytokine-induced reduction of VE-cadherin expression on immunofluorescence staining. Edaravone and dexamethasone increased the expression of ZO-1 at both the mRNA and protein levels. Edaravone and dexamethasone inhibited the permeability changes of human PMVEC, at least partly through an enhancement of VE-cadherin. Collectively, these results suggest a potential therapeutic approach for intervention in patients with ARDS.
Topics: Antigens, CD; Antipyrine; Cadherins; Capillary Permeability; Cells, Cultured; Cytokines; Dexamethasone; Edaravone; Endothelial Cells; Free Radical Scavengers; Humans; Intercellular Adhesion Molecule-1; Nitric Oxide Synthase; Zonula Occludens-1 Protein; omega-N-Methylarginine
PubMed: 26490025
DOI: 10.18926/AMO/53674 -
Annals of Biomedical Engineering Apr 2020tDCS has been used to treat various brain disorders and its mechanism of action (MoA) was found to be neuronal polarization. Since the blood-brain barrier (BBB) tightly...
tDCS has been used to treat various brain disorders and its mechanism of action (MoA) was found to be neuronal polarization. Since the blood-brain barrier (BBB) tightly regulates the neuronal microenvironment, we hypothesized that another MoA of tDCS is direct vascular activation by modulating the BBB structures to increase its permeability (P). To test this hypothesis, we used high resolution multiphoton microscopy to determine P of the cerebral microvessels in rat brain. We found that 20 min 0.1-1 mA tDCS transiently increases P to a small solute, sodium fluorescein (MW 376) and to a large solute, Dextran-70k, with a much higher increase in P to the large solute. By pretreating the vessel with a nitric oxide synthase inhibitor, we revealed that the tDCS-induced increase in P is NO dependent. A transport model for the BBB was further employed to predict the structural changes by the tDCS. Comparing model predictions with the measured data suggests that tDCS increases P by temporarily disrupting the structural components forming the paracellular pathway of the BBB. That the transient and reversible increase in the BBB permeability also suggests new applications of tDCS such as a non-invasive approach for brain drug delivery through the BBB.
Topics: Animals; Blood-Brain Barrier; Dextrans; Drug Delivery Systems; Female; Fluorescein; Nitric Oxide Synthase; Permeability; Rats, Sprague-Dawley; Transcranial Direct Current Stimulation; omega-N-Methylarginine
PubMed: 31916126
DOI: 10.1007/s10439-020-02447-7 -
Journal of Applied Physiology... May 2015Inhibition of nitric oxide synthase (NOS) significantly attenuates the increase in skeletal muscle glucose uptake during contraction/exercise, and a greater attenuation...
Inhibition of nitric oxide synthase (NOS) significantly attenuates the increase in skeletal muscle glucose uptake during contraction/exercise, and a greater attenuation is observed in individuals with Type 2 diabetes compared with healthy individuals. Therefore, NO appears to play an important role in mediating muscle glucose uptake during contraction. In this study, we investigated the involvement of neuronal NOSμ (nNOSμ), the main NOS isoform activated during contraction, on skeletal muscle glucose uptake during ex vivo contraction. Extensor digitorum longus muscles were isolated from nNOSμ(-/-) and nNOSμ(+/+) mice. Muscles were contracted ex vivo in a temperature-controlled (30°C) organ bath with or without the presence of the NOS inhibitor N(G)-monomethyl-l-arginine (L-NMMA) and the NOS substrate L-arginine. Glucose uptake was determined by radioactive tracers. Skeletal muscle glucose uptake increased approximately fourfold during contraction in muscles from both nNOSμ(-/-) and nNOSμ(+/+) mice. L-NMMA significantly attenuated the increase in muscle glucose uptake during contraction in both genotypes. This attenuation was reversed by L-arginine, suggesting that L-NMMA attenuated the increase in muscle glucose uptake during contraction by inhibiting NOS and not via a nonspecific effect of the inhibitor. Low levels of NOS activity (~4%) were detected in muscles from nNOSμ(-/-) mice, and there was no evidence of compensation from other NOS isoform or AMP-activated protein kinase which is also involved in mediating muscle glucose uptake during contraction. These results indicate that NO regulates skeletal muscle glucose uptake during ex vivo contraction independently of nNOSμ.
Topics: AMP-Activated Protein Kinases; Animals; Arginine; Biological Transport; Enzyme Inhibitors; Female; Glucose; Male; Mice; Mice, Inbred C57BL; Mice, Knockout; Muscle Contraction; Muscle, Skeletal; Nitric Oxide; Nitric Oxide Synthase Type I; Physical Conditioning, Animal; omega-N-Methylarginine
PubMed: 25749441
DOI: 10.1152/japplphysiol.00056.2015 -
Applied Physiology, Nutrition, and... Jul 2015High-fat diets are associated with an increased risk of cardiovascular disease. A potential underlying mechanism for the increased cardiovascular risk is endothelial...
High-fat diets are associated with an increased risk of cardiovascular disease. A potential underlying mechanism for the increased cardiovascular risk is endothelial dysfunction. Nitric oxide (NO)-mediated endothelium-dependent vasodilation is critical in the regulation of vascular tone and overall vascular health. The aim of this study was to determine the influence of dietary fat intake on endothelium-dependent vasodilation. Forty-four middle-aged and older sedentary, healthy adults were studied: 24 consumed a lower fat diet (LFD; 29% ± 1% calories from fat) and 20 consumed a high-fat diet (HFD; 41% ± 1% calories from fat). Four-day diet records were used to assess fat intake, and classifications were based on American Heart Association guidelines (<35% of total calories from fat). Forearm blood flow (FBF) responses to acetylcholine, in the absence and presence of the endothelial NO synthase inhibitor N(G)-monomethyl-l-arginine (L-NMMA), as well as responses to sodium nitroprusside were determined by plethysmography. The FBF response to acetylcholine was lower (∼15%; P < 0.05) in the HFD group (4.5 ± 0.2 to 12.1 ± 0.8 mL/100 mL tissue/min) than in the LFD group (4.6 ± 0.2 to 14.4 ± 0.6 mL/100 mL tissue/min). L-NMMA significantly reduced the FBF response to acetylcholine in the LFD group (∼25%) but not in the HFD group. There were no differences between groups in the vasodilator response to sodium nitroprusside. These data indicate that a high-fat diet is associated with endothelium-dependent vasodilator dysfunction due, in part, to diminished NO bioavailability. Impaired NO-mediated endothelium-dependent vasodilation may contribute to the increased cardiovascular risk with high dietary fat intake.
Topics: Acetylcholine; Adult; Aged; Analysis of Variance; Diet, High-Fat; Dietary Fats; Endothelium, Vascular; Feeding Behavior; Female; Humans; Male; Middle Aged; Nitric Oxide Synthase Type III; Nitroprusside; Plethysmography; Risk Factors; Vasodilation; omega-N-Methylarginine
PubMed: 26058441
DOI: 10.1139/apnm-2015-0006 -
British Journal of Clinical Pharmacology Oct 2014A major feature of endothelial dysfunction is reduced endothelium-dependent vasodilation, which in ageing may be due to decreased production of endothelial prostacyclin,...
AIM
A major feature of endothelial dysfunction is reduced endothelium-dependent vasodilation, which in ageing may be due to decreased production of endothelial prostacyclin, or nitric oxide (NO), or both.
METHOD
We tested this hypothesis in 12 younger (age 18-38 years, six women) and 12 older healthy adults (age 55-73 years, six post-menopausal women). Endothelium-dependent vasodilation was assessed by the forearm vascular conductance (FVC) response to intra-arterial acetylcholine (ACh) (0.5, 1.0, 2.0, 4.0 μg dl(-1) forearm tissue min(-1) ) before and 90 min after inhibition of the enzyme cyclo-oxygenase-2 (COX-2) with oral celecoxib (400 mg), followed by the addition of endothelial NO synthase inhibition with intra-arterial N(G) -monomethyl-l arginine acetate (L-NMMA).
RESULTS
Ageing was associated with a significantly reduced FVC response to ACh (P = 0.009, age-by-dose interaction; highest dose FVC ± SEM in ageing: 11.2 ± 1.4 vs. younger: 17.7 ± 2.4 units, P = 0.02). Celecoxib did not reduce resting FVC or the responses to ACh in any group. L-NMMA significantly reduced resting FVC and the responses to ACh in all groups, and absolute FVC values following L-NMMA were similar between groups.
CONCLUSION
In healthy normotensive younger and older adults, there is minimal contribution of prostacyclin to ACh-mediated vasodilation, yet the NO component of vasodilation is reduced with ageing. In the clinical context, these findings suggest that acute administration of medications that inhibit prostacyclin (i.e. COX-2 inhibitors) evoke modest vascular consequences in healthy persons. Additional studies are necessary to test whether chronic use of COX-2 medications reduces endothelium dependent vasodilation in older persons with or without cardiovascular risk factors.
Topics: Acetylcholine; Adolescent; Adult; Age Factors; Aged; Cyclooxygenase 2 Inhibitors; Endothelium, Vascular; Female; Humans; Male; Middle Aged; Nitric Oxide; Vasodilation; Young Adult; omega-N-Methylarginine
PubMed: 24698105
DOI: 10.1111/bcp.12397 -
Alcoholism, Clinical and Experimental... Apr 2019Maternal consumption of alcohol produces abnormalities in the developing fetus and can contribute to an increased incidence of many cardiovascular-related diseases. The...
BACKGROUND
Maternal consumption of alcohol produces abnormalities in the developing fetus and can contribute to an increased incidence of many cardiovascular-related diseases. The first goal of this study was to determine whether in utero exposure to alcohol influences reactivity of cerebral arterioles in adult (12 to 15 weeks old) rats. The second goal of this study was to examine whether in utero exposure to alcohol increased the susceptibility of the brain to damage following an ischemic event in adult rats.
METHODS
We fed Sprague Dawley dams a liquid diet with or without alcohol (3% ethanol) for the duration of their pregnancy (21 to 23 days). In the first series of studies, we examined reactivity of cerebral arterioles to endothelial nitric oxide synthase (eNOS)- (adenosine diphosphate [ADP]) and neuronal nitric oxide synthase (nNOS)-dependent N-methyl-D-aspartate (NMDA, and NOS-independent agonists in adult rats before and during application of l-NMMA. In another series of studies, we examined infarct volume following middle cerebral artery occlusion in adult offspring exposed to alcohol in utero. In both series of studies, we also determined the role for an increase in oxidative stress by feeding dams apocynin for the duration of their pregnancy.
RESULTS
We found that in utero exposure to alcohol reduced responses of cerebral arterioles to ADP and NMDA, but not to nitroglycerin in adult rats. In addition, treatment of the dams with apocynin prevented this impairment in cerebral vascular function. We also found that in utero exposure to alcohol worsened brain damage following ischemia/reperfusion in adult rats and that treatment of dams with apocynin prevented this increase in brain damage following ischemia/reperfusion.
CONCLUSIONS
We suggest that our findings may have important implications for the pathogenesis of brain abnormalities associated with fetal alcohol exposure.
Topics: Acetophenones; Adenosine Diphosphate; Animals; Arterioles; Brain; Enzyme Inhibitors; Ethanol; Excitatory Amino Acid Agonists; Female; Infarction; Infarction, Middle Cerebral Artery; Male; N-Methylaspartate; Nitroglycerin; Pregnancy; Prenatal Exposure Delayed Effects; Rats; Reperfusion Injury; omega-N-Methylarginine
PubMed: 30748017
DOI: 10.1111/acer.13979 -
EuroIntervention : Journal of EuroPCR... Apr 2015To investigate in vivo relationships between segmental wall shear stress (WSS), endothelium-dependent vasoreactivity and arterial remodelling.
AIMS
To investigate in vivo relationships between segmental wall shear stress (WSS), endothelium-dependent vasoreactivity and arterial remodelling.
METHODS AND RESULTS
Twenty-four patients with minor angiographic coronary arterial disease (≤30% stenosis severity) underwent intracoronary (IC) salbutamol provocation during intravascular ultrasound (IVUS)-upon-Doppler guidewire imaging. Macrovascular response (change in segmental lumen volume [SLV] at baseline and following IC salbutamol), plaque burden (percent atheroma volume [PAV]), remodelling indices (RI), eccentricity indices (EI) and WSS were evaluated in 179 consecutive 5 mm coronary segments. Baseline WSS was directly related to endothelium-dependent epicardial coronary vasomotion (% change SLV, coefficient 17.2, p=0.004), and inversely related to RI (coefficient -0.23, p=0.02) and EI (coefficient -10.0, p=0.001). Baseline WSS was lower in segments displaying endothelial dysfunction (defined as any change in SLV ≤0) compared with preserved function (0.66±0.33 vs. 0.71±0.22 N/m2, p=0.046). Independent of plaque burden, segments with the lowest tertile of WSS displayed less vasodilatation, or vasoconstriction, than segments with the highest tertile of WSS. Higher plaque burden segments harbouring the lowest tertiles of WSS displayed vasoconstriction, expansive arterial remodelling and greater plaque eccentricity.
CONCLUSIONS
In patients with stable coronary syndromes and minor angiographic coronary disease, coronary segments with lower in vivo WSS values display functional and morphological features of plaque vulnerability.
Topics: Adrenergic beta-2 Receptor Agonists; Albuterol; Coronary Angiography; Coronary Artery Disease; Coronary Stenosis; Coronary Vessels; Endothelium, Vascular; Enzyme Inhibitors; Female; Humans; Male; Middle Aged; Severity of Illness Index; Shear Strength; Ultrasonography, Doppler; Ultrasonography, Interventional; Vascular Remodeling; Vasodilation; omega-N-Methylarginine
PubMed: 24425248
DOI: 10.4244/EIJV10I12A249 -
Antiviral Chemistry & Chemotherapy Apr 2017L-N-monomethyl-arginine (L-NMMA) is an experimental compound that suppresses nitric oxide production in animals. The compound was combined with oseltamivir to treat...
L-N-monomethyl-arginine (L-NMMA) is an experimental compound that suppresses nitric oxide production in animals. The compound was combined with oseltamivir to treat lethal influenza A/California/04/2009 (H1N1) pandemic virus infections in mice. Treatments were given twice a day for five days starting 4 h (oseltamivir, by oral gavage) or three days (L-NMMA, by intraperitoneal route; corresponding to the time previously reported for nitric oxide induction in the animals) after infection. Low doses of oseltamivir were used in order to demonstrate synergy or antagonism. Oseltamivir monotherapy protected 70% of mice from death at 1 mg/kg/day. L-NMMA (40 and 80 mg/kg/day) was ineffective alone in preventing mortality. Compared to oseltamivir treatment alone, L-NMMA combined with oseltamivir was synergistically effective (as evaluated by three-dimensional MacSynergy analysis), resulting in survival increases from 20 to 70% when 40 or 80 mg/kg/day of L-NMMA was combined with 0.3 mg/kg/day of oseltamivir, and from 70 to 100% survival increases when these doses were combined with 1 mg/kg/day of oseltamivir. These data demonstrate that a nitric oxide inhibitor such as L-NMMA has the potential to be beneficial when combined with oseltamivir in treating influenza virus infections.
Topics: Animals; Antiviral Agents; Disease Models, Animal; Drug Synergism; Enzyme Inhibitors; Female; Influenza A Virus, H1N1 Subtype; Mice; Mice, Inbred BALB C; Orthomyxoviridae Infections; Oseltamivir; omega-N-Methylarginine
PubMed: 28417640
DOI: 10.1177/2040206617691885 -
Cardiovascular Diabetology May 2016Impaired vasoreactivity is often observed in subjects with metabolic syndrome, a condition that includes the presence of a specific cluster of risk factors for obesity...
BACKGROUND
Impaired vasoreactivity is often observed in subjects with metabolic syndrome, a condition that includes the presence of a specific cluster of risk factors for obesity and cardiovascular disease. However, hierarchical causes in the impaired vasoreactivity have not been clarified. We evaluated the impact of individual metabolic risk components or its clustering under the condition of insulin resistance on endothelial and smooth muscle cell function.
METHODS
Vascular reactivity to acetylcholine (Ach), with or without nitric oxide synthase (NOS) inhibitor N (G)-monomethyl-L-arginine (L-NMMA), or sodium nitroprusside (SNP) by forearm venous occlusion plethysmography and insulin sensitivity index (M mg/kg/min) in euglycemic clamp were measured in men without (n = 18, control group) or with (n = 19, metabolic syndrome group) metabolic syndrome.
RESULTS
(1) Ach-induced maximal forearm blood flow (maxFBF) was impaired in subjects with metabolic syndrome. In particular, the NOS-dependent component of Ach-induced maxFBF was selectively decreased, while the NOS-independent component remained relatively unchanged. (2) Ach-induced maxFBF and ∆Ach-induced maxFBF with L-NMMA were correlated with waist circumference, glucose, and triglycerides, and most strongly correlated with visceral fat area, adiponectin, and M. (3) Multivariate regression analysis indicated that individual metabolic risk components explained Ach-induced maxFBF by 4-21 %. Clustering of all metabolic risk components increased this to 35 %, and the presence of metabolic syndrome explained 30 %, indicating that defining metabolic syndrome can effectively predict impairment of endothelial dysfunction.
CONCLUSIONS
Endothelial dysfunction was correlated with individual metabolic risk components, but more strongly with clustering of the components under a condition with low insulin sensitivity. We suggest that in subjects with metabolic syndrome, endothelial function is impaired by multiple cardiovascular risk factors exclusively when under the condition of insulin insensitivity and also that defining metabolic syndrome can effectively predict impairment of endothelial dysfunction.
Topics: Acetylcholine; Adult; Aged; Cardiovascular Diseases; Endothelium, Vascular; Forearm; Humans; Male; Middle Aged; Myocytes, Smooth Muscle; Nitroprusside; Obesity; Regional Blood Flow; Risk Factors; Vasodilation; Vasodilator Agents; omega-N-Methylarginine
PubMed: 27188597
DOI: 10.1186/s12933-016-0394-5