Nitric oxide (NO) is a major gasotransmitter involved in several physiological processes of male reproduction. There is, nevertheless, little information concerning the role of NO during semen storage. The aim of this study was to evaluate the effect of NO on boar semen stored at 17oC for 72 h. For this purporse, sperm samples were treated with 0.625, 1.25, 2.5, 5, and 10 mM aminoguanidine (AG) or Nω-Nitro-L-arginine methyl ester hydrochloride (L-NAME), a selective and non-selective NO synthase (NOS) inhibitor, respectively. Moreover, sodium nitroprusside (SNP), a NO donor, was used at the dose of 18.75, 37.5, 75, and 150 μM. Sperm motility, membrane integrity, and acrosomal status were evaluated at 0, 4, 24, 48, and 72 h of semen storage. A significant increase of the amplitude of lateral sperm head displacement (ALH), and both curvilinear and straight-line velocity (VCL and VSL, respectively) was observed at 72 h of semen storage in samples treated with 0.625 mM AG, probably because of the antioxidant properties of this NOS inhibitor. Contrarily, 0.625 mM L-NAME showed no effect on boar sperm parameters during the entire period of semen storage. Moreover, AG and L-NAME at 10 mM negatively affected sperm kinetics and acrosome integrity, which may provide further support to the notion that low NO levels are necessary for a normal sperm function. The concentrations of SNP used in this study had mostly no or negative effects on boar sperm parameters during semen storage. In conclusion, the results from this study increase the understanding of the role of NO on boar sperm physiology.

• MeSH
• akrozom účinky léků   MeSH
• buněčná membrána účinky léků   MeSH
• časové faktory MeSH
• guanidiny farmakologie   MeSH
• motilita spermií účinky léků   MeSH
• nitroprusid farmakologie   MeSH
• oxid dusnatý aplikace a dávkování   farmakologie   MeSH
• prasata * MeSH
• spermie účinky léků   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   metabolismus   MeSH
• uchování spermatu veterinární   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Neuronal nitric oxide synthase (nNOS) is a target for development of antineurodegenerative agents. Most nNOS inhibitors mimic l-arginine and have poor bioavailability. 2-Aminoquinolines showed promise as bioavailable nNOS inhibitors but suffered from low human nNOS inhibition, low selectivity versus human eNOS, and significant binding to other CNS targets. We aimed to improve human nNOS potency and selectivity and reduce off-target binding by (a) truncating the original scaffold or (b) introducing a hydrophilic group to interrupt the lipophilic, promiscuous pharmacophore and promote interaction with human nNOS-specific His342. We synthesized both truncated and polar 2-aminoquinoline derivatives and assayed them against recombinant NOS enzymes. Although aniline and pyridine derivatives interact with His342, benzonitriles conferred the best rat and human nNOS inhibition. Both introduction of a hydrophobic substituent next to the cyano group and aminoquinoline methylation considerably improved isoform selectivity. Most importantly, these modifications preserved Caco-2 permeability and reduced off-target CNS binding.

• MeSH
• aminochinoliny chemická syntéza   farmakologie   MeSH
• Caco-2 buňky MeSH
• enzymatické testy MeSH
• histidin chemie   MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• myši MeSH
• permeabilita buněčné membrány účinky léků   MeSH
• skot MeSH
• synthasa oxidu dusnatého, typ I antagonisté a inhibitory   chemie   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   MeSH
• synthasa oxidu dusnatého, typ III antagonisté a inhibitory   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• myši MeSH
• skot MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Excess nitric oxide (NO) produced by neuronal nitric oxide synthase (nNOS) is implicated in neurodegenerative disorders. As a result, inhibition of nNOS and reduction of NO levels is desirable therapeutically, but many nNOS inhibitors are poorly bioavailable. Promising members of our previously reported 2-aminoquinoline class of nNOS inhibitors, although orally bioavailable and brain-penetrant, suffer from unfavorable off-target binding to other CNS receptors, and they resemble known promiscuous binders. Rearranged phenyl ether- and aniline-linked 2-aminoquinoline derivatives were therefore designed to (a) disrupt the promiscuous binding pharmacophore and diminish off-target interactions and (b) preserve potency, isoform selectivity, and cell permeability. A series of these compounds was synthesized and tested against purified nNOS, endothelial NOS (eNOS), and inducible NOS (iNOS) enzymes. One compound, 20, displayed high potency, selectivity, and good human nNOS inhibition, and retained some permeability in a Caco-2 assay. Most promisingly, CNS receptor counterscreening revealed that this rearranged scaffold significantly reduces off-target binding.

• MeSH
• aminochinoliny chemie   farmakokinetika   farmakologie   MeSH
• Caco-2 buňky MeSH
• fenylethery chemie   farmakokinetika   farmakologie   MeSH
• inhibitory enzymů chemie   farmakokinetika   farmakologie   MeSH
• krystalografie rentgenová MeSH
• lidé MeSH
• molekulární modely MeSH
• synthasa oxidu dusnatého, typ I antagonisté a inhibitory   metabolismus   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   metabolismus   MeSH
• synthasa oxidu dusnatého, typ III antagonisté a inhibitory   metabolismus   MeSH
• synthasa oxidu dusnatého antagonisté a inhibitory   metabolismus   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Coumarins represent a large group of 1,2-benzopyrone derivatives which have been identified in many natural sources and synthetized as well. Several studies have shown that their antioxidant capacity is not based only on direct scavenging of reactive oxygen and nitrogen species (RONS) but other mechanisms are also involved. These include: a) the chelation of transient metals iron and copper, which are known to catalyse the Fenton reaction; and b) the inhibition of RONS-producing enzymes (e.g. xanthine oxidase, myeloperoxidase and lipoxygenase), suggesting that mechanism(s) involved on cellular level are complex and synergistic. Moreover, many factors must be taken into account when analysing structure-antioxidant capacity relationships of coumarins due to different in vitro/in vivo methodological approaches. The structural features necessary for the direct RONS scavenging and metal chelation are apparently similar and the ideal structures are 6,7-dihydroxy- or 7,8-dihydroxycoumarins. However, the clinical outcome is unknown, because these coumarins are able to reduce copper and iron, and may thus paradoxically potentiate the Fenton chemistry. The similar structural features appear to be associated with inhibition of lipoxygenase, probably due to interference with iron in its active site. Contrarily, 6,7-dihydroxycoumarin seems to be the most active coumarin in the inhibition of xanthine oxidase while its derivative bearing the 4-methyl group or 7,8-dihydroxycoumarin are less active or inactive. In addition, coumarins may hinder the induction of inducible NO-synthase and cyclooxygenase- 2. Sparse data on inhibition of myeloperoxidase do not enable any clear conclusion, but some coumarins may block it.

• MeSH
• chelátory chemie   metabolismus   farmakologie   MeSH
• cyklooxygenasa 2 metabolismus   MeSH
• inhibitory enzymů chemie   metabolismus   farmakologie   MeSH
• kumariny chemie   metabolismus   farmakologie   MeSH
• lidé MeSH
• lipoxygenasa metabolismus   MeSH
• měď chemie   metabolismus   MeSH
• oxidační stres účinky léků   MeSH
• peroxidasa antagonisté a inhibitory   metabolismus   MeSH
• reaktivní formy kyslíku antagonisté a inhibitory   metabolismus   MeSH
• scavengery volných radikálů chemie   metabolismus   farmakologie   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   metabolismus   MeSH
• vztahy mezi strukturou a aktivitou MeSH
• xanthinoxidasa antagonisté a inhibitory   metabolismus   MeSH
• železo chemie   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Two major effector systems are frequently implicated in the immune and endothelial cell alternations associated with inflammation. They include the enhanced production of reactive oxygen species and diminished bioavailability of nitric oxide (NO). Importantly, these processes can be regulated by endogenously produced methylarginines, inhibitors for NO derived from macrophages and endothelial cells. Therefore, the aim of this study was to show the potential pharmacological intervention of methylarginines (N(G)-methyl-L-arginine, L-NMMA; N(G), N(G)'-dimethyl-L-arginine-symmetric dimethylarginine, SDMA; and N(G), N(G)-dimethyl-L-arginine-asymmetric dimethylarginine, ADMA) in activation of murine peritoneal (RAW 264.7) and alveolar (MHS) macrophages with lipopolysaccharide from Gram-negative bacteria (LPS). The data presented in this study clearly declare that L-NMMA (1-50μM) and ADMA (10-50 μM) significantly inhibited the LPS-induced NO production from macrophages in a concentration-dependent manner. It was demonstrated, for the first time, that the ADMA- and L-NMMA-induced down regulation of NO production was accompanied by reduced expression of mRNA and protein for inducible NO synthase as well as decreased activation of nuclear factor-κB. Importantly, we found a negative correlation between the ADMA-dependent reduction of NO production and ADMA-increased superoxide formation, which indicates that ADMA can negatively affect the balance in LPS-induced macrophage-derived production of reactive mediators. The only effect of SDMA was observed for LPS-triggered superoxide production, which was significantly decreased in its highest concentration (50 μM). In summary, L-NMMA and ADMA can mediate their effects on macrophage activation via regulation of intracellular signaling pathways, which can affect critical functions in activated macrophages.

• MeSH
• alveolární makrofágy účinky léků   imunologie   metabolismus   MeSH
• arginin analogy a deriváty   chemie   farmakologie   MeSH
• buněčné kultury MeSH
• buněčné linie MeSH
• exprese genu účinky léků   MeSH
• lipopolysacharidy toxicita   MeSH
• myši MeSH
• NF-kappa B antagonisté a inhibitory   biosyntéza   genetika   MeSH
• oxid dusnatý biosyntéza   MeSH
• peritoneální makrofágy účinky léků   imunologie   metabolismus   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• superoxidy metabolismus   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   biosyntéza   genetika   MeSH
• viabilita buněk účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Dietary supplementation with L-arginine was shown to improve immune responses in various inflammatory models. However, the molecular mechanisms underlying L-arginine effects on immune cells remain unrecognized. Herein, we tested the hypothesis that a limitation of L-arginine could lead to the uncoupled state of murine macrophage inducible nitric oxide synthase and, therefore, increase inducible nitric-oxide-synthase-derived superoxide anion formation. Importantly, we demonstrated that L-arginine dose- and time dependently potentiated superoxide anion production in bacterial endotoxin-stimulated macrophages, although it did not influence NADPH oxidase expression and activity. Detailed analysis of macrophage activation showed the time dependence between LPS-induced iNOS expression and increased O(2)(∙-) formation. Moreover, downregulation of macrophage iNOS expression, as well as the inhibition of iNOS activity by NOS inhibitors, unveiled an important role of this enzyme in controlling O(2)(∙-) and peroxynitrite formation during macrophage stimulation. In conclusion, our data demonstrated that simultaneous induction of NADPH oxidase, together with the iNOS enzyme, can result in the uncoupled state of iNOS resulting in the production of functionally important levels of O(2)(∙-) soon after macrophage activation with LPS. Moreover, we demonstrated, for the first time that increased concentrations of L-arginine further potentiate iNOS-dependent O(2) (∙-) formation in inflammatory macrophages.

• MeSH
• aktivace enzymů MeSH
• arginin imunologie   MeSH
• biopteriny analogy a deriváty   metabolismus   MeSH
• buněčné linie MeSH
• časové faktory MeSH
• Escherichia coli imunologie   MeSH
• inhibitory enzymů farmakologie   MeSH
• lipopolysacharidy škodlivé účinky   MeSH
• makrofágy účinky léků   imunologie   metabolismus   MeSH
• myši MeSH
• NADPH-oxidasy metabolismus   MeSH
• NG-nitroargininmethylester farmakologie   MeSH
• oxid dusnatý metabolismus   MeSH
• respirační vzplanutí MeSH
• superoxidy metabolismus   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   metabolismus   MeSH
• tyrosin analogy a deriváty   metabolismus   MeSH
• viabilita buněk MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• adiponektin farmakologie   fyziologie   MeSH
• agregace trombocytů fyziologie   účinky léků   MeSH
• antioxidancia metabolismus   MeSH
• dietní tuky metabolismus   MeSH
• financování organizované MeSH
• fosforylace MeSH
• hyperlipidemie metabolismus   MeSH
• krysa rodu rattus MeSH
• oxid dusnatý metabolismus   MeSH
• oxidační stres fyziologie   účinky léků   MeSH
• potkani Sprague-Dawley MeSH
• rekombinantní proteiny farmakologie   MeSH
• superoxidy metabolismus   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   metabolismus   MeSH
• synthasa oxidu dusnatého, typ III metabolismus   MeSH
• trombocyty metabolismus   účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH

• Klíčová slova
• subklinický zánět, inducibilní syntáza oxidu dusnatého, S-nitrosylace,
• MeSH
• diabetes mellitus 2. typu farmakoterapie   patofyziologie   prevence a kontrola   MeSH
• financování organizované MeSH
• inzulinová rezistence fyziologie   genetika   MeSH
• krysa rodu rattus MeSH
• lidé MeSH
• myši MeSH
• obezita patofyziologie   MeSH
• oxid dusnatý fyziologie   škodlivé účinky   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   fyziologie   chemie   MeSH
• synthasa oxidu dusnatého klasifikace   MeSH
• zánět patofyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• přehledy 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

Glucagon and ?-adrenergic-induced glycogenolysis is realized via the agonist/adenylyl cyclase/cAMP/protein kinase signaling pathway or via the activation of phosphorylase kinase by the mobilized calcium that supports the inhibition of glycogen synthase, respectively. The role of nitric oxide (NO) in this process has not been extensively studied. The present work was directed to the question whether NO is produced during glucagon-induced glycogenolysis in rat hepatocyte in a similar way like ?-adrenoceptor stimulation. Glycogen-rich hepatocyte cultures were used. NO production (NO2 -) was assessed under the influence of glucagon, dibutyryl cyclic AMP (db-cAMP), forskolin, the nitric oxide synthase (NOS) inhibitors N?-nitro-Larginine methyl ester (L-NAME) and aminoguanidine, and the NO donor S-nitroso-N-acetyl penicillamine (SNAP). Inducible NOS (iNOS) mRNA was examined by reverse transcription-polymerase chain reaction. Glycogenolysis was followed up by estimation of medium glucose levels. The amount of glucose and NO2 - released by glycogen-rich hepatocytes was increased as a result of glucagon, db-cAMP, forskolin and SNAP treatments. iNOS gene expression was upregulated by glucagon. Glycogenolysis that occurs through glucagon receptor stimulation involves NO production downstream of transduction pathways through an isoform of NO synthase. The present and previous studies document possible involvement of NO signaling in glycogenolytic response to glucagon and adrenergic agonists in hepatocytes.

• Klíčová slova
• Nitric oxide, Glucagon, Glycogenolysis, Hepatocytes,
• MeSH
• dibutyryl cyklický AMP farmakologie   MeSH
• donory oxidu dusnatého farmakologie   MeSH
• financování organizované MeSH
• glukagon farmakologie   MeSH
• glukosa metabolismus   MeSH
• glykogen biosyntéza   MeSH
• guanidiny farmakologie   MeSH
• hepatocyty metabolismus   účinky léků   MeSH
• kolforsin farmakologie   MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• oxid dusnatý biosyntéza   fyziologie   MeSH
• polymerázová řetězová reakce s reverzní transkripcí MeSH
• potkani Wistar MeSH
• S-nitroso-N-acetylpenicilamin farmakologie   MeSH
• separace buněk MeSH
• signální transdukce účinky léků   MeSH
• synthasa oxidu dusnatého, typ II antagonisté a inhibitory   biosyntéza   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH