Nitric oxide (NO) binds with high affinity to the heme of soluble guanylyl cyclase (sGC), resulting in accumulation second messenger cGMP many biological systems. 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) was recently described as potent and selective inhibitor sGC, providing an invaluable tool which settle function pathway NO-mediated signal transduction [Mol. Pharmacol. 48:184-188 (1995)]. The present study investigated mechanism ODQ-induced inhibition purified bovine lung sGC....

Nitric oxide (NO), a physiologically important activator of soluble guanylyl cyclase (sGC), is synthesized from l-arginine and O₂ in reaction catalyzed by NO synthases (NOS). Previous studies with purified NOS failed to detect formation free NO, presumably due fast inactivation simultaneously produced superoxide (O·̄₂). To characterize the products involved NOS-induced sGC activation, we measured cyclic 3′,5′-guanosine monophosphate (cGMP) incubated absence presence GSH...

Peroxynitrite (ONOO−) is widely recognized as mediator of NO toxicity, but recent studies have indicated that this compound may also physiological activity and induce vascular relaxation well inhibition platelet aggregation. We found ONOO− induced a pronounced increase in endothelial cyclic GMP levels, effect was significantly attenuated by pretreatment the cells with GSH-depleting agents. In presence 2 mM GSH, stimulated purified soluble guanylyl cyclase half-maximally effective...

The properties of neuronal nitric oxide synthase containing one tetrahydrobiopterin (BH4) per dimer [nNOS(BH4+)] were compared to those the BH4-free enzyme [nNOS(BH4-)]. stimulation by BH4 formation L-citrulline at expense H2O2 production unambiguously demonstrated that is essential in coupling reductive oxygen activation Arg oxidation. clear difference between Stokes radii nNOS(BH4-) and nNOS(BH4+) indicates introduction significantly changes structure. Whereas heme was primarily high-spin,...

Peels are an abundant but still underutilized waste product in the Citrus fruit industry. They contain coumarins with antiadipogenic potential that could be promising targets new valorization strategies for peels. In this study, these coumarins, is, citropten, bergamottin, and 5-geranyloxy-7-methoxycoumarin (5G7MC), were investigated limon peels of different commercial varieties by HPLC-DAD after extraction ethanol choline chloride-based natural deep eutectic solvents (NADES) as alternative...

We investigated how pH affects rat brain neuronal nitric oxide synthase (nNOS) with regard to spin-state equilibrium and the thiolate ligand bond of haem group, catalytic activity, monomerleft right arrow dimer equilibrium. At neutral pH, nNOS containing 1 equiv. (6R)-5,6,7,8-tetrahydro-l-biopterin (BH4) per was mostly high-spin (lambdamax at 398 nm), whereas BH4-free enzyme consisted a mixture two low-spin forms 418 nm, 376 456 nm respectively). With nNOS, an appreciable fraction only...

Aldehyde dehydrogenase-2 (ALDH2) catalyzes vascular bioactivation of the antianginal drug nitroglycerin (GTN), resulting in activation soluble guanylate cyclase (sGC) and cGMP-mediated vasodilation. We have previously shown that a minor reaction ALDH2-catalyzed GTN bioconversion, accounting for about 5% main clearance-based turnover yielding inorganic nitrite, results direct NO formation concluded this pathway could provide link between metabolism sGC. However, lack detectable at...

Mitochondrial Ca2+ uptake regulates diverse endothelial cell functions and has also been related to nitric oxide (NO•) production. However, it is not entirely clear if the organelles support or counteract NO• biosynthesis by taking up Ca2+. The objective of this study was verify whether mitochondrial influences Ca2+-triggered generation synthase (eNOS) in an immortalized line (EA.hy926), respective primary human umbilical vein cells (HUVECs) eNOS-RFP (red fluorescent protein) expressing...

To investigate the role of tetrahydrobiopterin (BH4) in catalytic mechanism nitric oxide synthase (NOS), we analyzed spectral changes following addition oxygen to reduced oxygenase domain endothelial (NOS) presence different pteridines at −30 °C. In NG-hydroxy-l-arginine (NOHLA) and BH4 or 5-methyl-BH4, both which support NO synthesis, first observable species were mixtures high-spin ferric NOS (395 nm), NO-heme (439 oxyferrous complex (417 nm). With Arg, no clear intermediates could be...

Mn(III)tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP), described as a superoxide dismutase mimetic and peroxynitrite scavenger, has been used previously to investigate the cytotoxic potential of in several pathological models. Here we report on interference MnTMPyP with NO/cGMP signaling using cultured endothelial cells well purified soluble guanylyl cyclase (sGC) either activated by NO donor 2,2-diethyl-1-nitroso-oxyhydrazine sodium salt (DEA/NO) or reconstituted nitric oxide synthase...

BACKGROUND AND PURPOSE Adipose triglyceride lipase (ATGL) has been identified as a rate‐limiting enzyme of mammalian catabolism. Deletion the ATGL gene in mice results severe lipid accumulation variety tissues including heart. In present study we investigated cardiac function ATGL‐deficient and potential therapeutic effects PPARα γ agonists Wy14,643 rosiglitazone, respectively. EXPERIMENTAL APPROACH Hearts isolated from wild‐type (WT) ATGL(‐/‐) treated with (PPARα agonist), rosiglitazone...

Nitrosothiols are increasingly regarded as important participants in a range of physiological processes, yet little is known about their biological generation. can be formed from the corresponding thiols by nitric oxide reaction that requires presence oxygen and mediated reactive intermediates (NO₂ or N₂O₃) course NO autoxidation. Because autoxidation second order NO, it extremely slow at submicromolar concentrations, casting doubt on its relevance. In this paper we present evidence...

Systemic knockout of adipose triglyceride lipase (ATGL), the pivotal enzyme lipolysis, results in a murine phenotype that is characterized by progredient cardiac steatosis and severe heart failure. Since vascular dysfunction have been closely related numerous studies we investigated endothelium-dependent -independent vessel function ATGL mice. Aortic relaxation Langendorff perfusion experiments isolated hearts showed mice suffer from pronounced micro- macrovascular endothelial dysfunction....

The antioxidant 5-hydroxymethylfurfural (5-HMF) exerts documented beneficial effects in several experimental pathologies and is currently tested as an antisickling drug clinical trials. In the present study, we examined cardiovascular of 5-HMF elucidated mode action drug.

YC-1 is a direct activator of soluble guanylyl cyclase (sGC) and sensitizes the enzyme for activation by nitric oxide (NO) CO. Because potentiating effect on NO-induced cGMP formation in platelets smooth muscle cells has been shown to be substantially higher than observed with purified enzyme, synergism between heme ligands apparently more pronounced intact cell-free systems. Here, we investigated mechanisms underlying synergistic sGC NO endothelial cells. Stimulation enhanced accumulation...

Soluble guanylyl cyclase (sGC) is the major physiological target of sydnonimine-based vasodilators such as molsidomine. Decomposition sydnonimines results in stoichiometric formation nitric oxide (NO) and superoxide (O₂⨪), which rapidly react to form peroxynitrite. Inasmuch sGC activated by NO but not peroxynitrite, we investigated mechanisms underlying activation 3-morpholinosydnonimine (SIN-1). Stimulation purified bovine lung SIN-1 was found be strongly dependent on glutathione...

Cardiac oxidative stress has been implicated in the pathogenesis of hypertrophy, cardiomyopathy and heart failure. Systemic deletion gene encoding adipose triglyceride lipase (ATGL), enzyme that catalyzes rate-limiting step lipolysis, results a phenotype characterized by severe steatotic cardiac dysfunction. The objective present study was to investigate potential role ATGL deficiency. Hearts mice with global knockout were compared those cardiomyocyte-restricted overexpression wildtype...

To elucidate how thiols affect neuronal nitric oxide synthase (nNOS) we studied the binding of to tetrahydrobiopterin (BH4)-free nNOS. Dithiothreitol (DTT), 2-mercaptoethanol, and L- D-cysteine all bound heme with Kd values varying from 0.16 mM for DTT 41 L-cysteine. DTT, L-cysteine yielded absorbance spectra maxima at about 378 456 nm, indicative bisthiolate complexes; maximum 426 nm suggests neutral thiol. From results 2-mercaptoethanol deduced that in 2-mercaptoethanol-free, BH4-free nNOS...

Belonging to the class of so-called soluble guanylate cyclase (sGC) activators, cinaciguat and BAY 60-2770 are interesting therapeutic tools for treatment various cardiovascular pathologies. The drugs supposed preferentially stimulate oxidized or heme-depleted, but not native sGC. Since this concept has been challenged by studies demonstrating complete relaxation nondiseased vessels, study was designed reinvestigate mode action in greater detail. To purpose, effect studied on vessel tone...

Electronic cigarette refill liquids are commercially provided with a wide variety of flavoring agents. A recent study suggested that several common flavors may scavenge nitric oxide (NO) and cause endothelial dysfunction. It was the aim present to investigate effects these on NO/cyclic GMP-mediated signaling vascular relaxation. We tested agents for Ca2+-induced cGMP accumulation NO synthase activation in cultured cells. scavenging studied NO-activated soluble guanylate cyclase as release...

Background — Vasorelaxation to endothelial NO is mediated by activation of soluble guanylyl cyclase (sGC) and impaired hypercholesterolemia in animals humans. We investigated whether impacts expression function sGC. Methods Results White New Zealand rabbits (n=10 per group) received a standard diet for 16 weeks (SD16) (n=20) or 32 (SD32) cholesterol (7.5 g/kg) (CD16) (CD32), respectively. Another group followed (CD/SD). Aortic the α 1 -subunit sGC (sGC-α ) β (sGC-β was assessed Western blot....