Nitric oxide synthases (NOS) are a family of isoforms responsible for the synthesis of the potent dilator nitric oxide (NO). Expression of inducible NOS (iNOS) occurs in conditions of inflammation, and produces large amounts of NO. In pathological conditions iNOS is regarded as a harmful enzyme and is proposed to be a major contributor to diseases of the cardiovascular system such as atherosclerosis. In this review, we address the notion that iNOS is a detrimental enzyme in disease and discuss its potentially beneficial roles. Additionally, we describe other molecules associated with iNOS in diseases such as atherosclerosis, and current research on therapeutic inhibitors tested to reduced pathology associated with cardiovascular diseases (CVD).

• MeSH
• kardiovaskulární nemoci metabolismus   MeSH
• lidé MeSH
• oxid dusnatý metabolismus   MeSH
• synthasa oxidu dusnatého, typ II metabolismus   MeSH
• synthasa oxidu dusnatého metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

• Konspekt
• Obecná genetika. Obecná cytogenetika. Evoluce
• NLK Obory
• genetika, lékařská genetika
• cytologie, klinická cytologie
• patologie

Complex interactions of nitric oxide and other free radicals have been implicated in the pathogenesis of sepsis and organ dysfunction. We hypothesized that simultaneous inducible nitric oxide synthase inhibition (L-N6-[1-iminoethyl]-lysine [L-NIL]) and neutralization of superoxide (O2-) (4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl [Tempol]) would protect from detrimental consequences of long-term, volume-resuscitated, hyperdynamic porcine bacteremia. In this prospective, randomized, controlled experimental study, 16 anesthetized, mechanically ventilated and instrumented pigs were exposed to 24 h of continuous infusion of live Pseudomonas aeruginosa. After 12 h of hyperdynamic sepsis, animals were randomized to receive either vehicle (control, n = 8) or combination of L-NIL and Tempol (n = 8). Systemic and hepatosplanchnic hemodynamics, oxygen exchange, metabolism, ileal mucosal microcirculation and tonometry, oxidative stress and coagulation parameters were assessed before, 12, 18, and 24 h of P. aeruginosa infusion. Combined treatment inhibited sepsis-induced increase in plasma nitrate/nitrite, 8-isoprostane, and thiobarbituric acid reactive species concentrations, prevented hypotension, and reversed hyperdynamic circulation. Despite lower intestinal macrocirculation, combined regimen attenuated the otherwise progressive deterioration in ileal mucosal microcirculation and prevented mucosal acidosis. Treatment substantially attenuated mesenteric and hepatic venous acidosis, preserved sepsis-induced impairment of hepatosplanchnic redox state, and prevented the development of renal dysfunction. Finally, coinfusion of L-NIL and Tempol largely attenuated the sepsis-induced rise in plasma von Willebrand factor and thrombin-antithrombin complexes. Thus, hemodynamic, microcirculatory, metabolic, renal, and coagulation data indicate that combining inducible inhibition with cell permeable O2(-) radical scavenger afforded significant protection in porcine sepsis, thus suggesting an important interactive role of O2(-) and nitric oxide in mediating organ dysfunction.

• MeSH
• bakteriemie farmakoterapie   patofyziologie   MeSH
• cyklické N-oxidy farmakologie   MeSH
• financování organizované MeSH
• prasata fyziologie   mikrobiologie   MeSH
• pseudomonádové infekce farmakoterapie   patofyziologie   MeSH
• Pseudomonas aeruginosa fyziologie   MeSH
• scavengery volných radikálů farmakologie   MeSH
• spinové značení MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH

V danej práci sme sledovali zmeny v imunoreaktivite (IR) neuronálnej syntázy oxidu dusnatého (nNOS) v lumbálnych spinálnych gangliách (DRGs) po ischemicko/reperfúznom poškodení miechy. Ischémia (15 min.) bola navodená Fogartyho balónovým katétrom cez femorálnu artériu v lumbosakrálnej časti miechy s dobou reperfúzie 7 dní. Ide o spôsob navodenia oklúzie abdominálnej aorty, pri ktorom dochádza k obštrukcii prietoku krvi v zadných končatinách. Na znázornenie nitrergických nNOS pozitívnych neurónov bola použitá imunohistochemická metóda. Na 7. deň sme zmeny nNOS-IR v rezoch spinálnych ganglií L3, L4, L5 a L6 porovnali s kontrolnými hodnotami a štatisticky vyhodnotili. Imunoreaktivita nNOS v spinálnych gangliách L3, L4 a L5 bola signifikantne zvýšená v porovnaní s kontrolami. V spinálnom gangliu L6 nedošlo k štatisticky významným zmenám v nNOS-IR v porovnaní s kontrolou.

The changes of neuronal nitric oxide synthase (nNOS) immunoreactivity (IR) in lumbar dorsal root ganglia (DRGs) after ischemia/reperfusion injury of spinal cord were observed. Spinal cord ischemia (15 min) was induced by Fogarty catheter through the femoral artery in the lumbosacral part of spinal cord with a reperfusion period of 7 days. The occlusion of the abdominal aorta causes the blood flow obstruction in hind-limbs. The immunohistochemical method was used to depict nNOS immunopositive neurons. On 7th day the changes of nNOS-IR in L3, L4, L5 and L6 sections of dorsal root ganglia were compared with control values and statistically evaluated. Immunoreactivity of nNOS in DRGs L3, L4 and L5 was significantly higher when compared to control samples, but in L6 no such significant change was detected.

• MeSH
• finanční podpora výzkumu jako téma MeSH
• králíci MeSH
• modely u zvířat MeSH
• poranění míchy MeSH
• reperfuzní poškození enzymologie   MeSH
• spinální ganglia enzymologie   MeSH
• synthasa oxidu dusnatého analýza   MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH

Inducible NO synthase (NOS II) was proposed to play an important role in salt resistance of Dahl salt-resistant (SR/Jr) rats. Its chronic inhibition by specific inhibitors was accompanied by blood pressure (BP) elevation in animals subjected to high salt intake. The aim of our study was to evaluate 1) whether such inhibitors affect BP and/or its particular components (sympathetic tone and NO-dependent vasodilation) only under the conditions of high salt intake, and 2) whether similar BP effects are elicited after systemic or intracerebroventricular (icv) application of these inhibitors. Wistar rats fed Altromin diet (0.45 % NaCl) and SR/Jr rats fed either a low-salt (LS, 0.3 % NaCl) or a high-salt (HS, 4 % NaCl) diet were studied. Aminoguanidine (AMG) and 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT) were used as NOS II inhibitors. BP and its responses to acute blockade of renin-angiotensin system (captopril), sympathetic nervous system (pentolinium) and NO synthase (L-NAME) were measured in conscious cannulated rats. There were no significant changes of BP or its components in either Wistar rats or SR/Jr rats subjected to chronic inhibition of NOS II by peroral aminoguanidine administration (50 mg/kg/day for 4 weeks). This was true for SR/Jr rats fed either LS or HS diets. Furthermore, we have studied BP effects of chronic icv administration of both NOS II inhibitors in SR/Jr rats fed HS diet, but we failed to find any BP changes elicited by such treatment. In conclusion, inducible NO synthase does not participate in the resistance of SR/Jr rats to hypertensive effects of excess salt intake.

• MeSH
• chlorid sodný MeSH
• hypertenze * chemicky indukované   MeSH
• krevní tlak fyziologie   MeSH
• krysa rodu rattus MeSH
• kuchyňská sůl * MeSH
• oxid dusnatý MeSH
• potkani inbrední Dahl MeSH
• potkani Wistar MeSH
• synthasa oxidu dusnatého, typ II MeSH
• synthasa oxidu dusnatého MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Angiogenesis plays an important role in maintaining adequate oxygen delivery, and nitric oxide (NO) is a potential regulator of angiogenesis. NO is synthesized through three isoforms of NO synthase (NOS). It is hypothesized that the NO derived from inducible NOS (iNOS) may promote survival of ischemic tissue through angiogenesis. To test this hypothesis, we investigated the effect of iNOS deficiency (by L-NIL) on angiogenesis in a hindlimb ischemia model. METHODS: Thirty-two male wistar rats randomly divided into four groups. In groups 1 & 2, hindlimb ischemia was induced by ligation of femoral artery and they received L-NIL and saline respectively. The animals in groups 3 and 4 also received L-NIL and saline respectively without surgical procedure. After 21 days, the serum concentration of nitrite, capillary density and expression of HIF1alpha were determined. RESULTS: Serum nitrite levels were significantly lower in L-NIL groups (p<0.05). The capillary density in group 1 (ischemia+L-NIL) was significantly different from group 2 (ischemia+saline); group 1: 360.33+/-77.02, group 2: 549+/-81.85 /mm2, p<0.05) .In addition, expression of HIF1alpha was significantly increased in ischemic groups (p<0.05). CONCLUSION: Selective inhibition of iNOS by L-NIL inhibits angiogenesis in a hindlimb ischemic rat model. In addition, ischemia induces expression of HIF1alpha in hypoxic tissue.

• MeSH
• dusitany krev   MeSH
• fyziologická neovaskularizace účinky léků   MeSH
• ischemie patofyziologie   MeSH
• kapiláry anatomie a histologie   účinky léků   MeSH
• kosterní svaly krevní zásobení   MeSH
• krysa rodu rattus MeSH
• potkani Wistar MeSH
• synthasa oxidu dusnatého, typ II farmakologie   MeSH
• zadní končetina MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH

Jedním z charakteristických etiopatogenetických dějů podmiňujících vznik inzulínové rezistence a diabetes mellitus 2. typu je subklinický zánět, který primárně vzniká v tukové tkáni v důsledku její zvýšené infiltrace imunokompetentními buňkami. Ty jsou spolu s adipocyty významným zdrojem prozánětlivých cytokinů, které spouští prozánětlivé kaskády interferující s inzulínovou signální kaskádou na postreceptorové úrovni. Podle posledních studií sehrává podstatnou úlohu v tomto procesu inducibilní syntáza oxidu dusnatého. Obezita je spojena se zvýšenou expresí tohoto enzymu, nadprodukcí oxidu dusnatého a reaktivních dusíkových radikálů, které vedou k S-nitrosylaci proteinů inzulínové signální kaskády. Tato posttranslační modifikace snižuje jejich aktivitu, a tím přispívá k inzulínové rezistenci. Řada experimentálních studií prokázala, že zablokování inducibilní syntázy oxidu dusnatého vede ke zmírnění inzulínové rezistence a s ní spojených metabolických změn. Cílem tohoto přehledu je shrnout současné poznatky o fyziologii a patofyziologii oxidu dusnatého a jeho inducibilní syntázy ve vztahu k inzulínové rezistenci a ukázat perspektivy prevence a léčby inzulínové rezistence a diabetes mellitus 2. typu ovlivněním tohoto enzymu.

Subclinical inflammation that primarily arises in the adipose tissue as a result of its excessive infiltration by immunocompetent cells represents one of the typical etiopathogenetic mechanisms underlying the development of insulin resistance and type 2 diabetes. These cells together with adipocytes are the major source of proinflammatory cytokines triggering proinflammatory cascades that in turn interfere with postreceptor insulin signalling cascade. Recent studies have suggested that inducible nitric oxide synthase plays a key role in this process. Obesity is associated with increased inducible nitric oxide synthase mRNA expression, with subsequent overproduction of nitric oxide and reactive nitrogen species leading to S-nitrosylation of insulin signalling proteins. This posttranslational modification decreases their activity and eventually leads to insulin resistance. Number of experimental studies demonstrated that inhibition of inducible nitric oxide synthase attenuates insulin resistance. The aim of this review is to summarize the current knowledge about the physiology and patophysiology of nitric oxide and inducible nitric oxide synthase with respect to its relationship to insulin resistance and to suggest the possibility of improvement of insulin resistance and type 2 diabetes mellitus by modulating inducible nitric oxide synthase activity.

• Klíčová slova
• subklinický zánět, inducibilní syntáza oxidu dusnatého, S-nitrosylace, inzulínová signalizační kaskáda,
• MeSH
• aktivace enzymů imunologie   MeSH
• cytokiny imunologie   MeSH
• diabetes mellitus 2. typu imunologie   metabolismus   MeSH
• financování organizované MeSH
• inzulinová rezistence genetika   imunologie   MeSH
• oxid dusnatý metabolismus   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   metabolismus   škodlivé účinky   MeSH
• tuková tkáň imunologie   metabolismus   MeSH
• zánět imunologie   metabolismus   MeSH

Coagulation abnormalities have been implicated in the pathogenesis of sepsis and organ dysfunction. Nitric oxide (NO) is regarded as a critical mediator of many vascular pathologies, including sepsis. However, limited evidence is available to document a relationship between NO generated by inducible NO synthase (iNOS) and hemostatic abnormalities in sepsis. Therefore, we evaluated the effects of selective iNOS inhibition on markers of endothelial and coagulation homeostasis in a clinically relevant model of porcine bacteremia induced and maintained for 24 hours (h) with a continuous infusion of live P. aeruginosa. After 12 h of sepsis, animals received either vehicle (Control, n=7) or continuous infusion of selective iNOS inhibitor L-NIL (n=7). Before as well as 12, 18 and 24 h after starting P. aeruginosa following variables related to i) endothelial dysfunction (von Willebrand factor [vWf]; tissue plasminogen activator activity [t-PA]; ii) coagulation (thrombin-antithrombin complexes [TAT]; platelet count); iii) fibrinolysis (t-PA activity, activity of plasminogen activator inhibitor type 1 (PAI-1 act); and iv) oxidative/nitrosative stress (isoprostanes, nitrate/nitrite levels) were measured. L-NIL inhibited sepsis-induced increase in plasma nitrate/nitrite and isoprostanes concentrations, prevented hypotension and acidosis. L-NIL significantly attenuated sepsis-induced rise in plasma vWF and TAT. P. aeruginosa-induced drop in t-PA activity was blunted by iNOS inhibition, while increased PAI-1 and reduced platelet count were not reversed by the treatment. In conclusion, selective iNOS inhibition was associated with attenuation of sepsis-induced coagulation and endothelial dysfunction suggesting the interplay between mediators of vascular system and hemostatic balance. Reduction of oxidative stress probably contributes to the beneficial effects afforded by iNOS blockade.

• MeSH
• acidobazická rovnováha účinky léků   MeSH
• bakteriemie krev   metabolismus   mikrobiologie   patofyziologie   MeSH
• cévní endotel metabolismus   patofyziologie   účinky léků   MeSH
• fibrinogen účinky léků   MeSH
• financování organizované MeSH
• hemokoagulace účinky léků   MeSH
• inhibitory enzymů farmakologie   MeSH
• kardiovaskulární systém účinky léků   MeSH
• lysin analogy a deriváty   farmakologie   MeSH
• modely nemocí na zvířatech MeSH
• oxid dusnatý metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• pseudomonádové infekce krev   metabolismus   mikrobiologie   patofyziologie   MeSH
• Pseudomonas aeruginosa MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH

The aim of this work was to study the effects of resveratrol (RES) as compared to silymarin (SM) pretreatments on tert-butylhydroperoxide (tBH) induced apoptotic/necrotic markers in hepatocytes. Hepatocyte in cultures (48 h) and in perifused immobilized agarose threads (5h) were used as cellular systems. Hepatocyte apoptosis was estimated morphologically using Annexin-V combined with propidium iodide, or toluidine blue staining. Hepatocyte viability and functionality were evaluated by ALT and urea synthesis. Nitric oxide (NO) and carbon monoxide involvements were also examined. Resveratrol and silymarin reduced tBH-induced hepatocyte toxic effects in short term experiments (5h) as measured by a significant reduction in ALT and NO increase produced by tBH. Both inducible nitric oxide synthase (NOS-2) and hemoxygenase-1 (HO-1) gene expression were increased by tBH and reduced by both RES and SM pretreatments. Morphologically, there were ameliorations in both apoptotic and necrotic markers under RES treatment and were similar to biochemical findings. In addition, RES improved hepatocyte stability in both cellular systems. It may be concluded that resveratrol and sylimarin ameliorative effects on tBH hepatocyte toxicity are comparable; involve NOS-2 and HO-1 expression and should be re-evaluated in various in vitro and in vivo experimental conditions.

• MeSH
• alanintransaminasa MeSH
• analýza rozptylu MeSH
• apoptóza účinky léků   MeSH
• cytoprotekce MeSH
• financování organizované MeSH
• hemoxygenasa-1 metabolismus   MeSH
• hepatocyty metabolismus   účinky léků   ultrastruktura   MeSH
• imobilizované buňky MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• nádorové biomarkery metabolismus   MeSH
• oxid dusnatý metabolismus   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• potkani Wistar MeSH
• silymarin farmakologie   MeSH
• stilbeny farmakologie   MeSH
• synthasa oxidu dusnatého, typ II metabolismus   MeSH
• terc-butylhydroperoxid toxicita   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH

Neoangiogenesis and inhibition of apoptosis are two factors considered as major leading causes of tumorigenesis. NO, synthesized by NOS, plays an important role in tumour growth, dissemination and vascularization. Caspase-3 is an executive enzyme of apoptosis. The presented research work has been focused on the comparative evaluation of localization of the angiogenic and proapoptotic cytokines expressed in tonsillar diseases. The immunohistochemical reaction of eNOS, iNOS and caspase-3 in tonsillar cancer (N = 17), chronic tonsillitis (N = 11) and clinically healthy tonsils (N = 8) was detected. High eNOS occurrence in endothelial cells of highly vascularized regions in tonsillar cancer, variable eNOS expression in the vessels of lamina propria in chronic tonsillitis and high expression in the cytoplasm of endothelial cells of small veins in healthy tonsillar tissue was ascertained. Increased iNOS expression was found in cancer tissue in comparison with the healthy tonsils. Nevertheless, the highest expression of iNOS was found in chronic tonsillitis. Higher expression of caspase-3 was discovered in germinal centres of lymphoid follicles of the chronic tonsillitis tissue. However, the positivity in the interfollicular zone and surface squamous epithelium was weak only. Merely isolated caspase-3-positive cells were found in tonsillar cancer. Very low expression of caspase-3 was detected in the lymphatic follicles of the healthy tonsils. Research results showed high expression of eNOS in the carcinomatous tissue. The eNOS expression in chronic tonsillitis confirms its role in regulating the lymphocyte circulation. Low expression of caspase-3 in malignant epithelial cells of tonsillar cancer shows decreased capability of apoptosis compared to chronic tonsillitis tissue, where apoptosis seems to be rather frequent and concentrated in the germinal centres of lymphatic follicles. The differences in localization of eNOS and caspase-3 expression between benign and malignant processes may be a promising tool for precise morphological distinction of chronic inflammation and tumours.

• MeSH
• chronická nemoc MeSH
• cytokiny metabolismus   MeSH
• kaspasa 3 metabolismus   MeSH
• krční mandle enzymologie   patologie   MeSH
• lidé MeSH
• synthasa oxidu dusnatého, typ II metabolismus   MeSH
• synthasa oxidu dusnatého, typ III metabolismus   MeSH
• tonzilární nádory enzymologie   patologie   MeSH
• tonzilitida enzymologie   patologie   MeSH
• zdraví MeSH
• Check Tag
• lidé MeSH