Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 10 de 10
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Biomed Khim ; 62(5): 577-583, 2016 Jul.
Artigo em Russo | MEDLINE | ID: mdl-27797334

RESUMO

Optimal conditions for obtaining phosphatidylholine (PC) liposomes with lipoic acid (LA) are chosen that lead to the formation of nanoparticles with a size of 175¸284 nm with efficiency (extent) of inclusion of LA in liposomes equal 85% and characterized by a slow release of substance from the nanoparticles. The effect of "empty" liposomes and liposomal form of LA on platelet aggregation induced by arachidonic acid (AA) is established. It is found that liposomes with LА inhibit platelet aggregation, caused by AА, to 80%. In addition, it is shown that "empty" liposomes slightly (to 30%) suppress platelet aggregation, caused by AА. The amount of TBA-sensitive products in samples of platelet-rich plasma (PRP) incubated with liposomal LA is determined. It is shown that LA in the composition of liposomes retains its antioxidant properties, and the amount of products of lipid peroxidation in platelet-rich plasma decreases in a dose-dependent manner when arachidonic acid is used as an inductor of platelet aggregation. It is assumed that the antiplatelet action of the liposomal form of LА is induced by inhibition of the initiation of lipid peroxidation products caused by exogenous inducer AА. It is supposed that, after additional research, the liposomal form of LA can be considered as a new drug in complex treatment of cerebral ischemia.


Assuntos
Antioxidantes , Plaquetas/metabolismo , Fosfatidilcolinas/química , Inibidores da Agregação Plaquetária , Agregação Plaquetária/efeitos dos fármacos , Ácido Tióctico , Antioxidantes/química , Antioxidantes/farmacocinética , Antioxidantes/farmacologia , Preparações de Ação Retardada/química , Preparações de Ação Retardada/farmacocinética , Preparações de Ação Retardada/farmacologia , Humanos , Lipossomos , Inibidores da Agregação Plaquetária/química , Inibidores da Agregação Plaquetária/farmacocinética , Inibidores da Agregação Plaquetária/farmacologia , Ácido Tióctico/química , Ácido Tióctico/farmacocinética , Ácido Tióctico/farmacologia
2.
Biofizika ; 58(3): 495-500, 2013.
Artigo em Russo | MEDLINE | ID: mdl-24159819

RESUMO

Activation of neutrophils in the presence of gold nanoparticles is accompanied by the formation of free radical peroxidation products recording the flash of chemiluminescence. The basis for the activation mechanism has its origins most likely in the influence of the gold particles on the surface membrane potential of neutrophils. Investigation of changes in the fluorescence intensity of the negatively charged ANS probe on the surface of model membranes by adding different concentrations of gold nanoparticles indicates the change in the membrane surface charge density that can cause cell activation.


Assuntos
Radicais Livres/metabolismo , Ouro/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Nanopartículas Metálicas , Ativação de Neutrófilo/efeitos dos fármacos , Neutrófilos/metabolismo , Relação Dose-Resposta a Droga , Ouro/química , Humanos , Luminescência , Neutrófilos/citologia
3.
Biofizika ; 50(1): 13-9, 2005.
Artigo em Russo | MEDLINE | ID: mdl-15759498

RESUMO

The interaction of hypochlorite with linoleic acid hydroperoxides was studied by the coumarin C-525-enhanced chemiluminescence and ESR spin trapping techniques. Linoleic acid hydroperoxide was obtained in the reaction of lipoxygenase and linoleic acid. Alpha-(4-pyridyl-1-oxyl)-N-tert Butylnitron was used as a spin trap. It was shown that the addition of hypochlorite to the incubation media containing linoleic acid and lipoxygenase resulted in an intensive chemiluminescence flash. The intensity of this flash correlated with the hydroperoxide concentration. The analysis of ESR spectra of spin adducts produced in the reaction of hypochlorite with linoleic acid hydroperoxide showed the presence of O-centered, most likely peroxyl, radical with the splitting constants alphabetaH = 0.260 mT aN = 1.662 mT and C-centered penthyl radical with the splitting constants alphabetaH = 0.260 mT; aN = 1.662 mT. These data suggest that hypochlorite produced by phagocytes in vivo can induce the generation of free O- and C-centered radicals, promoters of free radical processes.


Assuntos
Radicais Livres/química , Ácido Hipocloroso/química , Peróxidos Lipídicos/química , Espectroscopia de Ressonância de Spin Eletrônica , Lipoxigenase/química , Luminescência , Marcadores de Spin
4.
Biofizika ; 47(5): 787-94, 2002.
Artigo em Russo | MEDLINE | ID: mdl-12397947

RESUMO

The interaction of hypochlorite (HOCl/OCl-) with tert-butyl hydroperoxide ((CH3)3COOH) was investigated by chemiluminescence. It was shown that the addition of HOCl/OCl- to (CH3)3COOH induces a fast chemiluminescent flash. The intensity of this flash increases with the increase in both HOCl/OCl- and (CH3)3COOH concentration. The chemiluminescence is quenched in a concentration-dependent manner in the presence of free radical spin traps N-tert-butyl nitrone and alpha-(4-pyridyl-1-oxyl)-N-tert-butyl nitrone. This fact proves that free radicals take part in the interaction of HOCl/OCl- and (CH3)3COOH. Hypochlorite yielded a very similar chemiluminescence spectrum in its reaction with (CH3)3COOH as Ce4+. It differed considerably from the spectrum in the system H2O2 and HOCl/OCl-. It is well known that the interaction of Ce4+ and (CH3)3COOH produces peroxyl radicals. These results confirm the hyothesis that the interaction of HOCl/OCl- and (CH3)3COOH is mediated by peroxyl radicals. Thus, organic hydroperoxides always present in unsaturated lipids can induce lipid peroxidation processes in the reaction with HOCl/OCl-.


Assuntos
Ácido Hipocloroso/química , Peróxidos/química , terc-Butil Hidroperóxido/química , Espectroscopia de Ressonância de Spin Eletrônica , Radicais Livres , Cinética , Medições Luminescentes
5.
Vestn Ross Akad Med Nauk ; (4): 48-52, 2000.
Artigo em Russo | MEDLINE | ID: mdl-10832415

RESUMO

The paper deals with the present views of some chemical properties and biological effects of nitric oxide (NO) and chiefly its formation and primary conversions. The interaction of NO with superoxide radical is shown to one of the most important reactions of the former, which gives rise to peroxynitrite whose breakdown yields a hydroxy radical. Emphasis is laid on the substances that are a temporary depot or a possible transport form of NO, such as nitrosothiols and nitrosyl complexes of non-hemic iron. NO is well-known to release when these compounds are degraded. It is suggested that hemoglobin is another NO depot, which forms stable complexes with the latter. These hemoglobin complexes may be degraded on exposure to laser radiation to form free NO that ha a vasodilatory effect. Photolysis of nitrosyl complexes of hemoglobin may be responsible for the therapeutical effect of laser radiation.


Assuntos
Hemoglobinas/fisiologia , Terapia a Laser , Óxido Nítrico/fisiologia , Animais , Heme/efeitos da radiação , Hemoglobinas/efeitos da radiação , Humanos , Óxido Nítrico/biossíntese , Óxido Nítrico/química , Óxido Nítrico/efeitos da radiação , Óxido Nítrico Sintase/metabolismo , Conformação Proteica/efeitos da radiação
6.
Biochemistry (Mosc) ; 62(6): 661-6, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9284548

RESUMO

Relaxation of blood vessel walls is one of the physiological effects induced by visible radiation. This effect is similar to the endothelium-derived relaxation (based on endothelium-derived relaxing factor, EDRF) and depends on the presence of nitric oxide donors. We assumed that nitric oxide hemoglobin (HbNO) might participate in the mechanism of this phenomenon and investigated the photochemical reactions using low-power He-Cd (441.6 nm) and He-Ne (632.8 nm) lasers. It was found that in the presence of oxygen the He-Cd laser but not He-Ne laser induced a photolytic decrease of the HbNO EPR signal amplitude by 25-35%. Using optical absorption measurements, we showed that methemoglobin was formed during irradiation. The comparison of the kinetics of this process and the irreversible reduction of paramagnetic centers suggest that the laser radiation leads to dissociation of the heme-NO complexes, but not to oxidation of the heme iron. In the absence of oxygen the photodissociation effect did not exceed 5-10% and was reversible. We suppose that this finding can be explained by fast reassociation of NO with unligated Hb. The EPR spectrum of iminonitroxide was observed upon irradiation of HbNo with nitronyl nitroxide in a vacuum, suggesting the formation of free NO. Thus, our experiments confirm that NO-hemoglobin can reversibly dissociate and release free NO during exposure to He-Cd laser radiation.


Assuntos
Hemoglobinas/química , Hemoglobinas/efeitos da radiação , Espectroscopia de Ressonância de Spin Eletrônica , Hemoglobinas/metabolismo , Humanos , Técnicas In Vitro , Cinética , Lasers , Óxido Nítrico/análise , Óxido Nítrico/metabolismo , Oxigênio , Fotoquímica , Vasodilatação/fisiologia , Vasodilatação/efeitos da radiação
7.
Biofizika ; 41(4): 876-86, 1996.
Artigo em Russo | MEDLINE | ID: mdl-8962887

RESUMO

High voltage electric field pulses, was shown previously, induced activation of blood neutrophil respiratory burst, registered as increase in luminol-dependent chemiluminescence of cell suspension. The quantitative analysis of this phenomenon by fluorescent probes and radioisotope methods have shown that electric pulse induced neutrophil chemiluminescence is a result of Ca2+ ions entering the cells through reversible pores in plasma membrane. Electric pulse of amplitude 5 kV/cm generates two tens of reversible pores with average diameter nearly 2 nm and lifetime 1 minute. Total amount of calcium penetrating at this conditions from the medium (1 mM Ca2+) into the cells was as high as 1.2 fmole/cell that is nearly 3.6 mM concentration per cell volume. Whereas the increase in the cytoplasmic concentration of free calcium did not exceed 1.3 microM, that is more then 3 order less. Data presented is discussed with relation to possible biological role of electroporation by natural electric fields presented in living systems.


Assuntos
Eletricidade , Ativação de Neutrófilo , Cálcio/metabolismo , Eletroporação , Corantes Fluorescentes , Humanos , Medições Luminescentes
9.
Biofizika ; 29(3): 480-2, 1984.
Artigo em Russo | MEDLINE | ID: mdl-6331853

RESUMO

Many data on the effect of millimeter (MM) radiation of low intensity (of the order of 1 mVt/cm2) on living organisms were accumulated [1]. The specifics of this effect is first of all manifested in frequency--selective (resonance) pattern of the biological system response and the effect of threshold dependence of exposition time and power of MM radiation. To study the mechanism of this effect it seems perspective to investigate the influence of radiation on the membrane transport. The present work investigated the effect of MM radiation on a comparatively simple and well investigated object--isolated frog skin.


Assuntos
Micro-Ondas , Pele/metabolismo , Sódio/metabolismo , Animais , Transporte Biológico/efeitos da radiação , Técnicas In Vitro , Potenciais da Membrana/efeitos da radiação , Rana temporaria , Pele/efeitos da radiação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...