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Zhongguo Zhong Yao Za Zhi = Zhongguo... Nov 2022This study was designed to determine the inhibitory effect of astragaloside Ⅳ(AS-Ⅳ), a principal bioactive component extracted from the Chinese medicinal Astragali...
This study was designed to determine the inhibitory effect of astragaloside Ⅳ(AS-Ⅳ), a principal bioactive component extracted from the Chinese medicinal Astragali Radix, on the inflammatory response of vascular endothelial cells induced by angiotensin Ⅱ(Ang Ⅱ), the most major pathogenic factor for cardiovascular diseases, and to clarify the role of calcium(Ca~(2+))/phosphatidylinosi-tol-3-kinase(PI3K)/protein kinase B(Akt)/endothelial nitric oxide synthase(eNOS)/nitric oxide(NO) pathway in the process. To be specific, human umbilical vein endothelial cells(HUVECs) were cultured in the presence of AS-Ⅳ with or without the specific inhibitor of NO synthase(NG-monomethyl-L-arginine, L-NMMA), inhibitor of PI3K/Akt signaling pathway(LY294002), or Ca~(2+)-chelating agent(ethylene glycol tetraacetic acid, EGTA) prior to Ang Ⅱ stimulation. The inhibitory effect of AS-Ⅳ on Ang Ⅱ-induced inflammatory response and the involved mechanism was determined with enzyme-linked immunosorbent assay(ELISA), cell-based ELISA assay, Western blot, and monocyte adhesion assay which determined the fluorescently labeled human monocytic cell line(THP-1) adhered to Ang Ⅱ-stimulated endothelial cells. AS-Ⅳ increased the production of NO by HUVECs in a dose-and time-dependent manner(P<0.05) and raised the level of phosphorylated eNOS(P<0.05). The above AS-Ⅳ-induced changes were abolished by pretreatment with L-NMMA, LY294002, or EGTA. Compared with the control group, Ang Ⅱ obviously enhanced the production and release of cytokines(tumor necrosis factor-α, interleukin-6), chemokines(monocyte chemoattractant protein-1) and adhesion molecules(intercellular adhesion molecule-1, vascular cellular adhesion molecule-1), and the number of monocytes adhered to HUVECs(P<0.05), which were accompanied by the enhanced levels of phosphorylated inhibitor of nuclear factor-κBα protein and activities of nuclear factor-κB(NF-κB)(P<0.05). This study also demonstrated that Ang Ⅱ-induced inflammatory response was inhibited by pretreatment with AS-Ⅳ(P<0.05). In addition, the inhibitory effect of AS-Ⅳ was abrogated by pretreatment with L-NMMA, LY294002, or EGTA(P<0.05). This study provides a direct link between AS-Ⅳ and Ca~(2+)/PI3K/Akt/eNOS/NO pathway in AS-Ⅳ-mediated anti-inflammatory actions in endothelial cells exposed to Ang Ⅱ. The results indicate that AS-Ⅳ attenuates endothelial cell-mediated inflammatory response induced by Ang Ⅱ via the activation of Ca~(2+)/PI3K/Akt/eNOS/NO signaling pathway.
Topics: Humans; Angiotensin II; Proto-Oncogene Proteins c-akt; Phosphatidylinositol 3-Kinases; omega-N-Methylarginine; Egtazic Acid; Human Umbilical Vein Endothelial Cells; NF-kappa B; Nitric Oxide; Cells, Cultured
PubMed: 36472009
DOI: 10.19540/j.cnki.cjcmm.20220725.701 -
The Journal of Physiology Nov 2021The importance of nitric oxide (NO) in regulating cerebral blood flow (CBF) remains unresolved, due in part to methodological approaches, which lack a comprehensive... (Randomized Controlled Trial)
Randomized Controlled Trial
The importance of nitric oxide (NO) in regulating cerebral blood flow (CBF) remains unresolved, due in part to methodological approaches, which lack a comprehensive assessment of both global and regional effects. Importantly, NO synthase (NOS) expression and activity appear greater in some anterior brain regions, suggesting region-specific NOS influence on CBF. We hypothesized that NO contributes to basal CBF in healthy adults, in a regionally distinct pattern that predominates in the anterior circulation. Fourteen healthy adults (7 females; 24 ± 5 years) underwent two magnetic resonance imaging (MRI) study visits with saline (placebo) or the NOS inhibitor, L-NMMA, administered in a randomized, single-blind approach. 4D flow MRI quantified total and regional macrovascular CBF, whereas arterial spin labelling (ASL) MRI quantified total and regional microvascular perfusion. L-NMMA (or volume-matched saline) was infused intravenously for 5 min prior to imaging. L-NMMA reduced CBF (L-NMMA: 722 ± 100 vs. placebo: 771 ± 121 ml/min, P = 0.01) with similar relative reductions (5-7%) in anterior and posterior cerebral circulations, due in part to the reduced cross-sectional area of 9 of 11 large cerebral arteries. Global microvascular perfusion (ASL) was reduced by L-NMMA (L-NMMA: 42 ± 7 vs. placebo: 47 ± 8 ml/100g/min, P = 0.02), with 7-11% reductions in both hemispheres of the frontal, parietal and temporal lobes, and in the left occipital lobe. We conclude that NO contributes to macrovascular and microvascular regulation including larger artery resting diameter. Contrary to our hypothesis, the influence of NO on cerebral perfusion appears regionally uniform in healthy young adults. KEY POINTS: Cerebral blood flow (CBF) is vital for brain health, but the signals that are key to regulating CBF remain unclear. Nitric oxide (NO) is produced in the brain, but its importance in regulating CBF remains controversial since prior studies have not studied all regions of the brain simultaneously. Using modern MRI approaches, a drug that inhibits the enzymes that make NO (L-NMMA) reduced CBF by up to 11% in different brain regions. NO helps maintain proper CBF in healthy adults. These data will help us understand whether the reductions in CBF that occur during ageing or cardiovascular disease are related to shifts in NO signalling.
Topics: Adult; Cerebrovascular Circulation; Female; Humans; Male; Nitric Oxide; Nitric Oxide Synthase; Perfusion; Regional Blood Flow; Single-Blind Method; Young Adult; omega-N-Methylarginine
PubMed: 34587648
DOI: 10.1113/JP281975 -
Nutrients Jun 2023Changes in serum concentration of methylarginines and amino acids after exercise are well documented, whereas the effects of exercise applied together with fasting are...
Changes in serum concentration of methylarginines and amino acids after exercise are well documented, whereas the effects of exercise applied together with fasting are still debated and not thoroughly studied. Thus, we hypothesised that alterations in methylarginines such as ADMA, SDMA and L-NMMA might be responsible for decreased exercise performance after 8 days of fasting. Additionally, we propose that conditions in which the human body is exposed to prolonged fasting for more than a week elicit a distinctly different response to exercise than after overnight fasting. A group of 10 healthy men with previous fasting experience participated in the study. The exercise test was performed until exhaustion with a gradually increasing intensity before and after the 8-day fast. Blood samples were collected before and immediately after exercise. ADMA, SDMA, L-NMMA, dimethylamine and amino acids were analysed in serum samples by ID-LC-MS/MS. SDMA, L-NMMA and dimethylamine significantly decreased after 8 days of fasting, whereas ADMA did not change. BCAA, Phe, alanine and some other amino acids increased after fasting. Exercise-induced changes in amino acids were distinct after an 8-day fast compared to overnight fasting. A decrease in physical performance accompanied all of these alterations. In conclusion, our data indicate that neither methyl-arginine changes nor the Trp/BCAA ratio can explain exercise-induced fatigue after fasting. However, the observed decrease in hArg concentration suggests the limited synthesis of creatine, possibly contributing to reduced physical performance.
Topics: Male; Humans; Amino Acids; omega-N-Methylarginine; Chromatography, Liquid; Tandem Mass Spectrometry; Arginine
PubMed: 37447307
DOI: 10.3390/nu15132981 -
Microcirculation (New York, N.Y. : 1994) Oct 2019To determine the ability of renal contrast-enhanced ultrasonography (CEUS) to detect acute drug-induced changes in renal perfusion (using the glucagon-like... (Randomized Controlled Trial)
Randomized Controlled Trial
Assessment of real-time and quantitative changes in renal hemodynamics in healthy overweight males: Contrast-enhanced ultrasonography vs para-aminohippuric acid clearance.
OBJECTIVE
To determine the ability of renal contrast-enhanced ultrasonography (CEUS) to detect acute drug-induced changes in renal perfusion (using the glucagon-like peptide (GLP)-1 receptor agonist exenatide and nitric oxide [NO]-synthase inhibitor L-N -monomethyl arginine [l-NMMA]), and assess its correlation with gold standard-measured effective renal plasma flow in humans.
METHODS
In this prespecified exploratory analysis of a placebo-controlled cross-over study, renal hemodynamics was assessed in 10 healthy overweight males (aged 20-27 years; BMI 26-31 kg/m ) over two separate testing days; during placebo (isotonic saline) and subsequent exenatide infusion (Day-A), and during l-NMMA, and subsequent exenatide plus l-NMMA infusion (Day-B). Renal cortical microvascular blood flow was estimated following microbubble infusion and CEUS destruction-refilling-sequences. Renal cortical microvascular blood flow was compared with simultaneously measured effective renal plasma flow in humans, derived from para-aminohippuric acid-clearance methodology.
RESULTS
On Day-A, effective renal plasma flow increased by 68 [26-197] mL/min/1.73 m during exenatide vs placebo infusion (+17%; P = .015). In parallel, exenatide increased renal cortical microvascular blood flow, from 2.42 × 10 [6.54 × 10 -4.66 × 10 ] AU to 4.65 × 10 [2.96 × 10 -7.74 × 10 ] AU (+92%; P = .027). On Day-B, effective renal plasma flow and renal cortical microvascular blood flow were reduced by l-NMMA, with no significant effect of concomitant exenatide on renal hemodynamic-indices assessed by either technique. Effective renal plasma flow correlated with renal cortical microvascular blood flow on Day-A (r = .533; P = .027); no correlation was found on Day-B.
CONCLUSIONS
Contrast-enhanced ultrasonography can detect acute drug-induced changes human renal hemodynamics. CEUS-assessed renal cortical microvascular blood flow moderately associates with effective renal plasma flow, particularly when perfusion is in normal-to-high range. Renal CEUS cannot replace effective renal plasma flow measurements, but may be a complementary tool to characterize regional kidney perfusion.
Topics: Adult; Blood Flow Velocity; Contrast Media; Humans; Kidney; Male; Microcirculation; Overweight; Pilot Projects; Ultrasonography; omega-N-Methylarginine
PubMed: 31313410
DOI: 10.1111/micc.12580 -
Oxidative Medicine and Cellular... 2020() is one of the most important agents of dermatophyte infection in humans. The aim of this experiment was to evaluate the effect of HaCaT cells on , investigate the...
() is one of the most important agents of dermatophyte infection in humans. The aim of this experiment was to evaluate the effect of HaCaT cells on , investigate the responsible mechanism of action, and explore the role of reactive oxygen species (ROS) and nitric oxide (NO) in the inhibition of growth by HaCaT cells. The viability of fungi treated with HaCaT cells alone and with HaCaT cells combined with pretreatment with the NADPH oxidase inhibitor (DPI) or the nitric oxide synthase (NOS) inhibitor L-NMMA was determined by enumerating the colony-forming units. NOS, ROS, and NO levels were quantified using fluorescent probes. The levels of the NOS inhibitor asymmetric dimethylarginine (ADMA) were determined by enzyme-linked immunosorbent assay (ELISA). Micromorphology was observed using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). In addition, fungal keratinase activity was assessed by measuring dye release from keratin azure. In vitro fungal viability, keratinase activity, and ADMA content decreased after HaCaT cell intervention, whereas the levels of ROS, NO, and NOS increased. The micromorphology was abnormal. Fungi pretreated with DPI and L-NMMA exhibited opposite effects. HaCaT cells inhibited the growth and pathogenicity of in vitro. A suggested mechanism is that ROS and NO play an important role in the inhibition of growth by HaCaT cells.
Topics: Arginine; Catecholamines; Cell Line; Enzyme Inhibitors; Humans; Imidazolines; Microscopy, Electron, Scanning; Microscopy, Electron, Transmission; NADPH Oxidases; Nitric Oxide; Nitric Oxide Synthase; Peptide Hydrolases; Reactive Oxygen Species; Trichophyton; omega-N-Methylarginine
PubMed: 32104540
DOI: 10.1155/2020/8548619 -
Molecules (Basel, Switzerland) May 2020(QM)-a member of the Fagaceae family-has been used as traditional medicine in Korea, China and Mongolia as a treatment for inflammation of oral, genital or anal mucosa...
(QM)-a member of the Fagaceae family-has been used as traditional medicine in Korea, China and Mongolia as a treatment for inflammation of oral, genital or anal mucosa and for external inflammation of skin. To treat acne vulgaris (AV), we evaluated the inhibition of inflammatory cytokines (IL-6 and IL-8) of QM leaf extract (QML) and its main compound, pedunculagin (PD) in vitro and 5α-reductase inhibitory activity by western blotting. As results, QML and PD showed potent NO production inhibitory activity compared with the positive control (PC), NG-monomethyl-L-arginine (L-NMMA). QML and PD was also showed the decreases of IL-6 and IL-8 compared with the PC, EGCG and exhibited potent 5α-reductase type 1 inhibitory activities compared with the PC, dutasteride.
Topics: 5-alpha Reductase Inhibitors; Acne Vulgaris; Anti-Inflammatory Agents; Cell Line; Cholestenone 5 alpha-Reductase; Down-Regulation; Humans; Interleukin-6; Interleukin-8; Lipopolysaccharides; Medicine, Traditional; Nitric Oxide; Plant Extracts; Plant Leaves; Quercus; Tannins; omega-N-Methylarginine
PubMed: 32380665
DOI: 10.3390/molecules25092154 -
Science Translational Medicine Dec 2021The inducible nitric oxide signaling (iNOS) pathway is associated with poor prognosis in triple-negative breast cancer (TNBC). Prior studies using in vivo models showed...
The inducible nitric oxide signaling (iNOS) pathway is associated with poor prognosis in triple-negative breast cancer (TNBC). Prior studies using in vivo models showed that inhibition of the iNOS signaling pathway using the pan-NOS inhibitor NG-monomethyl-l-arginine (L-NMMA) reduced tumor growth and enhanced survival in patients with TNBC. Here, we report a first-in-class phase 1/2 trial of L-NMMA combined with taxane for treating patients with chemorefractory, locally advanced breast cancer (LABC) or metastatic TNBC. We also examined immune cell correlates of chemotherapy response. 35 patients with metastatic TNBC were recruited: 15 in the phase 1 trial and 24 in the phase 2 trial (including 4 recommended phase 2 dose patients from the phase 1 trial). The overall response rate was 45.8% (11 of 24): 81.8% (9 of 11) for patients with LABC and 15.4% (2 of 13) for patients with metastatic TNBC. Among the patients with LABC, three patients had a pathological complete response at surgery (27.3%). Grade ≥3 toxicity was noted in 21% of patients; however, no adverse events were attributed to L-NMMA. Immune cells analyzed by CyTOF indicated that chemotherapy nonresponders showed greater expression of markers associated with M2 macrophage polarization and increased concentrations of circulating IL-6 and IL-10 cytokines. In contrast, chemotherapy responders showed an increase in CD15 neutrophils in blood, as well as a decrease in arginase (a marker of protumor N2 neutrophils) in tumor biopsies obtained at the end of treatment. L-NMMA combined with taxane warrants further investigation in larger clinical studies of patients with breast cancer.
Topics: Enzyme Inhibitors; Humans; Nitric Oxide; Nitric Oxide Synthase; Taxoids; Triple Negative Breast Neoplasms; omega-N-Methylarginine
PubMed: 34910551
DOI: 10.1126/scitranslmed.abj5070 -
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 -
Toxicology and Industrial Health 2024This toxicology study was conducted to assess the impact of formaldehyde, a common air pollutant found in Chinese gymnasiums, on the brain function of athletes. In this...
This toxicology study was conducted to assess the impact of formaldehyde, a common air pollutant found in Chinese gymnasiums, on the brain function of athletes. In this research, a total of 24 Balb/c male mice of SPF-grade were divided into four groups, each consisting of six mice. The mice were exposed to formaldehyde at different concentrations, including 0 mg/m, 0.5 mg/m, 3.0 mg/m, and 3.0 mg/m in combination with an injection of L-NMMA (N-monomethyl-L-arginine), which is a nitric oxide synthase antagonist. Following a one-week test period (8 h per day, over 7 days), measurements of biomarkers related to the nitric oxide (NO)/cGMP-cAMP signaling pathway were carried out on the experimental animals post-treatment. The study found that: (1) Exposure to formaldehyde can lead to brain cell apoptosis and neurotoxicity; (2) Additionally, formaldehyde exposure was found to alter the biomarkers of the NO/cGMP-cAMP signaling pathway, with some changes being statistically significant ( < 0.05 or < 0.01); (3) The use of L-NMMA, an antagonist of the NO/cGMP-cAMP signaling pathway, was found to prevent these biomarker changes and had a protective effect on brain cells. The study suggests that the negative impact of formaldehyde on the brain function of mice is linked to the regulation of the NO/cGMP-cAMP signaling pathway.
Topics: Humans; Male; Mice; Animals; omega-N-Methylarginine; Nitric Oxide; Mice, Inbred BALB C; Cyclic GMP; Formaldehyde; Signal Transduction; Brain; Biomarkers; Respiratory Hypersensitivity
PubMed: 37921628
DOI: 10.1177/07482337231210942