182 research outputs found

    Effects of nerve and fibroblast growth factors on the production of nitric oxide in experimental model of Huntington's disease

    Get PDF
    The role of nitric oxide (NO) in neurological diseases represents one of the most studied, yet controversial subjects in physiology. The aim was to examine the effects of intrastriatal injection neurotrophins (nerve growth factors-NGF, fibroblast growth factors-FGF) in order to investigate the possible involvement of NO in quinolinic acid (QA) induced striatum toxicity in the rat model of Huntington's disease (HD). QA was administered unilaterally into the striatum of adult Wistar rats in a single dose of 150 nM. The other two groups of animals were pretreated immediately before QA application with NGF and FGF, respectively. Control group was treated with 0.9% saline solution in the same manner. Animals were decapitated 7 days after the treatment. Nitrite levels were significantly decreased both in the ipsi- and contra lateral striatum and forebrain cortex of NGF- and FGF-treated animals compared with QA treatment. These results indicated a temporal and spatial propagation of oxidative stress and spread protective effects of NGF and FGF on the forebrain cortex, the distant structure, but tightly connected with striatum, the place of direct neurotoxin damage. Neurotrophins could be the potential neuroprotective agents in HD

    Efficient genetic transformation of Impatiens hawkerii Bull. (Balsamiaceae) using agrobacterium rhizogenes

    Get PDF
    Transformation of Impatiens hawkerii Bull. mediated by Agrobacterium rhizogenes strain A4M70GUS was studied. Hairy roots developed 10 days after inoculation were excised from the shoot explants and transferred onto Murashige and Skoog's (MS) basal medium lacking plant growth regulators. More than 20 hairy root clones were established and eight of them were further analyzed. Each clone differed significantly from the others in growth capacity and lateral branching. Clone C2 showed the highest biomass (20.6 g L-1) as well as the highest number of lateral roots (37 Ā± 2.2). The transgenic nature of the established hairy root clones was confirmed by GUS assay and PCR analysis. In conclusion, hairy roots were developed for the first time in I. hawkerii Bull., and transgenic hairy root clones showed a distinct morphological nature and growth patterns.Proučavana je genetička transformacija Impatiens hawkerii Bull. posredstvom Agrobacterium rhizogenes soja A4M70GUS. Deset dana posle inokulacije formirali su se transgeni korenovi na eksplantatima izdanaka, a zatim gajeni na Murashige and Skoog's (MS) osnovnoj hranljivoj podlozi bez biljnih regulatora rastenja. Uspostavljene su kulture viÅ”e od 20 klonova, a 8 je dalje analizirano. Klonovi su se međusobno značajno razlikovali u odnosu na kapacitet rastenja i bočnog grananja. Klon C2 je imao najveću biomasu (20.6 g L-1), kao i najveći broj bočnih korenova (37 Ā± 2.2). Prisustvo stranih gena u klonovima transgenih korenova je potvrđeno GUS eseja i PCR analize. Transgeni korenovi su dobijeni prvi put kod Impatiens hawkerii Bull. i pokazuju značajne razlike u morfologiji i parametrima rastenja.Projekat ministarstva br. TR-2301

    Effect of nitrogen salts on the growth of Ceratonia siliqua L. Shoot cultures

    Get PDF
    Effects of reduced nitrogen salt nutriton on the growth, lenticel hypertrophy and anthocyanin accumulation of carob (Ceratonia siliqua L.) shoot cultures were investigated in conditions of light and darkness. Growth of shoot cultures was not significantly affected until nitrogen salts were reduced to less than Ā¼ of full-strength MS (Murashige and Skoog, 1962) values. Cultures in darkness were less affected and their main shoots even increased in length. Appearance of hypertrophied lenticels in light decreased, while in darkness they were absent in all treatments. Reduced nitrogen salt nutrition strongly affected anthocyanin accumulation of shoots and leaves, which greatly increased in both light and darkness. .Kod kultura izdanaka rogača ispitivani su efekti smanjenja koncentracije azotnih soli u podlozi MS mineralnog rastvora na multiplikaciju i izduživanje izdanaka, hipertrofiju lenticela i sintezu i akumulaciju antocijanina na svetlosti i u mraku. Smanjenje koncentracije N u podlozi bitno menja parametre rastenja izdanaka (multiplikaciju i izduživanje) tek na Ā¼ (na svetlosti) tj. 1/10 (u mraku). Hipertrofirane lenticele se ne razvijaju na etioliranim izdancima gajenim u mraku dok su kod izdanaka gajenim na svetlosti brojne. Smanjenjem koncentracije N u podlozi broj HL se smanjuje kao i njihovo akropetalno prostiranje. Sinteza i akumulacija antocijanina u izdancima i listovima rogača bila je direktno zavisna od koncentracije N u podlozi i na svetlosti i u mraku. .nul

    Nitric oxide (NO) and an NMDA receptor antagonist in pentylenetetrazole-induced convulsions

    Get PDF
    Controversy about proconvulsant and anticonvulsant nitric oxide (NO) effects and the place of oxidative stress in convulsions, are still a matter of research. We investigated the interaction between 2-amino-5-phosphonovaleric acid (APV), a competitive N-methyl-D-aspartate (NMDA) receptor antagonist and Nw-nitro-L-arginine methyl ester (L-NAME), a nonselective nitric oxide synthase (NOS) antagonist, in pentylenetetrazole (PTZ)-induced convulsions. Pentylenetetrazole was applied to adult Wistar rats intraperitoneally (ip) in a single dose of 80 mg/kg, and L-NAME (10 Āµg/10 Āµl) or APV (20 Āµg/10 Āµl) intracerebroventricularly (icv), 30 and 10 minutes before PTZ, respectively. In the same manner, another group received both antagonists. Control animals were given 0.9% saline. Nw-nitro-L-arginine methyl ester exerted a weak anticonvulsant effect, preventing generalized clonic (GCC) and clonic-tonic convulsions (CTC) in 17% of cases. With APV protection against GCC and CTC was 100%, forelimb dystonia (FLD) was decreased in 33% of cases, and time to onset of all convulsive patterns was prolonged (p<0.05 to 0.01). All effects of APV, except in CTC, were reversed by L-NAME applied prior to APV. In APV-PTZ treated animals, superoxide anion content was increased in the forebrain cortex, striatum and hippocampus, without an overwhelmed antioxidative superoxide dismutase (SOD) defense system in the other treatments. When the APV-PTZ group was treated with L-NAME, both SOD activity and superoxide anion content were additionally decreased indicating that the NOS-NO system was involved in the metabolism of superoxide anions. It is suggested that clinical and biochemical effects of NO strongly depend upon the pretreatment and might lead to a wrong impression of NO contradictory activity.Kontroverzni nalazi o prokonvulzivnim kao i antikonvulzivnim efektima azot oksida (NO) i značaju oksidativnog stresa u konvulzijama, i dalje su predmet istraživanja. U konvulzijama izazvanim primenom pentilentetrazola (PTZ) ispitivali smo interakciju između 2-amino-5-fosfovalerinske kiseline (APV) kompetitivnog antagoniste N-metil-D-aspartat (NMDA) receptora i Nw-nitro-L-arginin metil estra (L-NAME), neselektivnog antagoniste azot oksid sintaze (NOS). Odraslim pacovima Wistar soja, PTZ je ubrizgavan intraperitonealno (ip) u jednoj dozi od 80 mg/kg. Ostale supstance, L-NAME (10 Āµg/10 Āµl) i APV (20 Āµg/10 Āµl), primenjivale su se intracerebroventrikularno (icv), i to L-NAME 30, a APV 10 minuta pre PTZ. Po istom vremenskom principu, jedna grupa dobila je oba antagonista, a kontrolna fizioloÅ”ki rastvor NaCl. Nw-nitro-L-arginin metil estar ispoljio je slabo antikonvulzivno dejstvo, smanjujući incidenciju generalizovanih kloničnih (GCC) i klonično-toničnih konvulzija (CTC) za 17%. Za razliku od L-NAME, APV je sprečila nastanak GCC i CTC kod svih životinja (100%), a incidencija klonusa prednjih nogu (FLD) smanjena je za 33%. Istovremeno primenom APV produženo je vreme od aplikacije PTZ do pojave svih konvulzivnih tipova (p<.05 do 0.01). Primenom L-NAME pre APV, umanjeni su efekti APV, pri čemu je doÅ”lo do povećanja incidencije FLD i GCC za 16% odnosno 50%. U kori prednjeg mozga, strijatumu i hipokampusu, životinja koje su dobile APV+PTZ, doÅ”lo do povećanja koncentracije superoksidnog anjona. Aktivnost superoksid dizmutaze ne prati ovaj skok. Njen dodatni pad u grupi tretiranoj sa L-NAME pre APV+PTZ, ukazuje da je sistem NOS-NO uključen u metabolizam superoksidnog anjona. Dobijeni rezultati ukazuju da klinički i biohemijski efekti NO u velikoj meri zavise od prethodno primenjenih supstanci i promena izazvanih njima, Å”to može da doprinose sticanju pogreÅ”nog utiska o kontradiktornim dejstvima NO.nul

    Antioxidative effect of nerve growth factor (NGF) in rat thalamus after quinolinic acid-induced neurotoxicity

    Get PDF
    Quinolinic acid (QA) produces a pattern of selective cell loss in the striatum, that closely mimics that of Huntington's disease (HD). The aim of this study was to investigate the antioxidative status in the thalamus after intrastriatal application of QA and the influence of nerve growth factor (NGF) on such neurotoxicity. Wistar rats were treated intrastriatally (coordinates: 8.4A, 2.6L, 4.8V), using a stereotaxic instrument. The first group was treated with QA (150 nmol/l). The second group was treated with QA, followed by NGF (4.5 mg/kg b.w). The control group was treated with 0.9 % saline solution. Seven days after the treatment, we found decreased superoxide dismutase (SOD) activity in mitochondrial fractions of the striatum of both groups. In the thalamus, SOD activity showed no differences. The content of superoxide anion increased in the striatum of QA- treated animals. It was decreased in both structures in the group that was treated with QA and NGF. In the QA+ NGF-treated group, we found increased glutathione peroxidase (GSHPx) and GSH, compared to the group that was treated with QA only, but these values were lower than in the controls. Thus, NGF showed beneficial effects on the oxido-reduction status in the striatum, and also in the thalamus, a structure that is separated from but tightly connected with the striatum.Hinolinska kiselina (HK) prouzrokuje takav selektivni gubitak ćelija u strijatumu, koji veoma dobro imitira onaj kod Huntingtonove bolesti. Cilj ovog istraživanja bio je da se ispita antioksidativni status u talamusu nakon aplikacije HK u strijatum i uticaj NGF na takvu neurotoksičnost. Wistar pacovi su tretirani intrastrijatno, pomoću stereotaksičnog instrumenta (koordinate: 8,4A, 2,6L, 4,8V). Prva grupa je bila tretirana HK (150 nmol/l). Druga grupa je bila tretirana HK, a nakon toga je dobila NGF (4.5 mg/ kg b.w). Kontrolna grupa je bila tretirana fizioloÅ”kim rastvorom. Sedam dana nakon tretmana, u mitohondrijskim frakcijama strijatuma, naÅ”li smo smanjenu aktivnost SOD u obema grupama. U talamusu, aktivnost SOD se nije promenila. Sadržaj superoksidnog anjona se povećao u strijatumu životinja koje su bile tretirane HK, a smanjio se u obema strukturama, u grupi koja je bila tretirana sa HK i NGF. U HK+ NGF-tretiranoj grupi, naÅ”li smo povećanu aktivnost GSHPx i GSH u odnosu na grupu koja je bila tretirana samo sa HK, ali su te vrednosti bile manje u odnosu na kontrolne. NGF je pokazao povoljne efekte na oksido-reduktivni status u strijatumu, ali takođe i u talamusu, strukturi koja je odvojena, ali veoma blisko povezana sa strijatumom.nul

    What Is Special about Aromatic-Aromatic Interactions? Significant Attraction at Large Horizontal Displacement

    Get PDF
    High-level ab initio calculations show that the most stable stacking for benzene-cyclohexane is 17% stronger than that for benzene-benzene. However, as these systems are displaced horizontally the benzene-benzene attraction retains its strength. At a displacement of 5.0 ƅ, the benzene-benzene attraction is still āˆ¼70% of its maximum strength, while benzene-cyclohexane attraction has fallen to āˆ¼40% of its maximum strength. Alternatively, the radius of attraction (>2.0 kcal/mol) for benzene-benzene is 250% larger than that for benzene-cyclohexane. Thus, at relatively large distances aromatic rings can recognize each other, a phenomenon that helps explain their importance in protein folding and supramolecular structures
    • ā€¦
    corecore