Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 230
Filtrar
1.
Klin Med (Mosk) ; 94(7): 527-32, 2016.
Artigo em Russo | MEDLINE | ID: mdl-30289218

RESUMO

We investigated the association of polymorphisms of genes tumor necrosis factors and their receptors (-308G/A TNFa, +250A/G Lta, +36 A/G TNFR1, +1663 A/G TNFR2) with the predisposition to the development of essential hypertension (EH) and the features of its clinical course in patients with metabolic syndrome. It has been demonstrated that the molecular genetic marker +36G TNFR1 (OR=1,25) is involved in the formation EH in individuals with metabolic syndrome. The risk of stage III EH in patients with metabolic syndrome is enhanced by genetic variants -308GA TNFa (OR=2,72), -308A TNFa (OR=2,72), +250G Lta (OR=1,80), and combinations thereof -308A TNFa with +1663G TNFR2 (OR=3,85), +250G Lta with +36G TNFR1 (OR=3,85), +250G Lta with +1663G TNFR2 (OR=3,85) while protective properties are inherent in -308GG TNFa (OR=0,32), +250AA Lta (OR=0,45), -308G TNFa (OR=0,37), +250A Lta (OR=0,56) and a combination of genetic markers -308GG TNFa with +250A Lta (OR=0,31), -308G TNFa with +250AA Lta (OR=0,39), -308G TNFa with +250A Lta (OR=0,31).


Assuntos
Hipertensão , Síndrome Metabólica , Receptores do Fator de Necrose Tumoral , Fator de Necrose Tumoral alfa/genética , Adulto , Idoso , Feminino , Marcadores Genéticos , Predisposição Genética para Doença , Humanos , Hipertensão/complicações , Hipertensão/genética , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/genética , Pessoa de Meia-Idade , Polimorfismo Genético , Receptores do Fator de Necrose Tumoral/classificação , Receptores do Fator de Necrose Tumoral/genética , Federação Russa
2.
Klin Med (Mosk) ; 94(5): 333-8, 2016.
Artigo em Russo | MEDLINE | ID: mdl-30289643

RESUMO

The article is a review of recent epidemiological observations concerning the prevalence of overweight and obesity in different countries among people of different gender, age. social and ethnic groups. It also presents and analyses health risks and comorbidities leading to disability and death as reported by domestic and foreign researchers. It was found that obesity has multifactorial pathogenesis directly related to energy balance, consumed and expended calories. The need of a multidisciplinary approach to the treatment and prevention of the disease is emphasized taking into consideration the influence of the environment and increasing urbanization on the development of the pathology as well as the role of government efforts to stimulate physical activity of the population in the framework of integral interdisciplinary programs and control over the quality of food. The priority areas for the correction of overweight include optimization of motor activity and diet correction.


Assuntos
Estilo de Vida , Obesidade , Serviços Preventivos de Saúde/organização & administração , Comportamento de Redução do Risco , Causalidade , Humanos , Obesidade/epidemiologia , Obesidade/prevenção & controle , Prevalência
3.
Klin Med (Mosk) ; 94(6): 450-4, 2016.
Artigo em Russo | MEDLINE | ID: mdl-30289663

RESUMO

Most clinicians consider duodenum ulcer as a psychosomatic disease. Objective: To show the interdependence of this condition and mental disorders and their relation to disturbances of melatonin production . Materials and Methods: 15 patients with seasonal DU and 15 healthy subjects of the control group were examined during 3 years using laboratory, endoscopic, and standard psychodiagnostic methods. Results. It was found that all patients with exacerbation of DU experienced enhanced anxiety, reduced background mood, and impaired quality of life based on general health and mental health scoring scales. The circadian rhythm of melatonin production was markedly distorted throughout the observation period but especially during exacerbations of the disease. Conclusions. The results indicate a high degree of correlation between DU and mental disorders caused by impaired production of melatonin. It suggests common etiological mechanisms of DU and psychosomatic symptom complex.


Assuntos
Ansiedade , Depressão , Úlcera Duodenal , Melatonina , Transtornos Psicofisiológicos , Qualidade de Vida , Ansiedade/diagnóstico , Ansiedade/fisiopatologia , Fenômenos Cronobiológicos , Ritmo Circadiano , Depressão/diagnóstico , Depressão/fisiopatologia , Úlcera Duodenal/diagnóstico , Úlcera Duodenal/fisiopatologia , Úlcera Duodenal/psicologia , Duodenoscopia/métodos , Feminino , Humanos , Masculino , Melatonina/análise , Melatonina/biossíntese , Pessoa de Meia-Idade , Testes Psicológicos , Transtornos Psicofisiológicos/diagnóstico , Transtornos Psicofisiológicos/metabolismo , Transtornos Psicofisiológicos/fisiopatologia , Estatística como Assunto , Inquéritos e Questionários
4.
Klin Med (Mosk) ; 92(4): 35-40, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25269207

RESUMO

The study showed that ulcer disease in patients with metabolic syndrome is characterized by painless clinical course, bowel disorders in the form of constipation, enhanced appetite, unmotivated requirement for hypoglycemic therapy predisposition to complications along with activation of the inflammatory process in duodenal mucosa, high H. pylori count. The data obtained were used to develop the age-specific strategy for the treatment of elderly patients with duodenal ulcer and concomitant metabolic syndrome.


Assuntos
Comorbidade , Úlcera Duodenal/fisiopatologia , Síndrome Metabólica/fisiopatologia , Polimedicação , Fatores Etários , Idoso , Úlcera Duodenal/tratamento farmacológico , Úlcera Duodenal/epidemiologia , Humanos , Masculino , Síndrome Metabólica/tratamento farmacológico , Síndrome Metabólica/epidemiologia , Pessoa de Meia-Idade
5.
Klin Med (Mosk) ; 92(7): 5-11, 2014.
Artigo em Russo | MEDLINE | ID: mdl-25775898

RESUMO

The basis of the highly effective method for diagnostics of many dangerous diseases with the use of breathing tests and stable 13C isotope-labeled preparations has been developed in Russia during the past years. The technology for manufacturing 13C-preparations using domestically produced starting materials satisfies the requirements for isotopes in this and many foreign countries. New instruments for respiratory tests and diagnostic methods make it possible to carry out diagnostics in large populations including that in the course of regular medical examination. This paper reports high efficacy of 13C-based breath tests for diagnostics of gastrointestinal disorders, possibilities and prospects for their further application in oncology, endocrinology, pulmonology, neurology, cardiology, surgery, etc. Special attention is given to the use of 13C-magnetic resonance techniques for visualization of tumours and blood vessels, studies of metabolic processes and energy balance in man and animals with the use of 13C-biomarkers. The main advantages of these new diagnostic approaches are high accuracy, safety (for both patients and personnel), simplicity, and possibility of application in different fields of medicine.


Assuntos
Testes Respiratórios/métodos , Isótopos de Carbono , Análise Espectral , Isótopos de Carbono/farmacologia , Humanos , Medicina Interna , Reprodutibilidade dos Testes , Especialidades Cirúrgicas , Análise Espectral/instrumentação , Análise Espectral/métodos
6.
Klin Med (Mosk) ; 89(3): 9-14, 2011.
Artigo em Russo | MEDLINE | ID: mdl-21861395

RESUMO

Part 1 of this review is devoted to modern concepts of mechanisms of action of weak natural and artificial electromagnetic fields (EMF) on the cardiovascular system at the cellular, molecular, and atomic levels with the participation of Ca2+ and melatonin. EMF are known to affect Ca2+ homeostasis and suppress melatonin activity in a wide wavelength range. Ca2+ ions in pinealocytes are involved in regulation of cAMP synthesis that mediates conversion of serotonin into melatonin. Their leakage from pinealocytes results in a decrease of the cAMP level and thereby suppresses production of melatonin. At the same time, the cyclic circadian rhythm of melatonin secretion controls the overall activity of human body from eating to sleep and metabolism.


Assuntos
Ritmo Circadiano/efeitos da radiação , Doença das Coronárias/metabolismo , Campos Eletromagnéticos , Hipertensão/metabolismo , Melatonina/fisiologia , Doença das Coronárias/fisiopatologia , Humanos , Hipertensão/fisiopatologia
7.
Transl Psychiatry ; 1: e31, 2011 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-22832605

RESUMO

Alzheimer's disease (AD), a progressive neurodegenerative disorder, is the leading cause of dementia in the elderly. A recent positron emission tomography imaging study demonstrated upregulated brain arachidonic acid (AA) metabolism in AD patients. Further, a mouse model of AD shows an increase in AA-releasing cytosolic phospholipase A(2) (cPLA(2)) in brain, and a reduction in cPLA(2) activity ameliorated cognitive deficits. These observations led us to hypothesize that there is an upregulation of AA cascade and neuroinflammatory markers in the brain of AD patients. To test this hypothesis, we measured protein and mRNA levels of AA cascade, neuroinflammatory and synaptic markers in postmortem frontal cortex from 10 AD patients and 10 age-matched controls. Consistent with our hypothesis, AD frontal cortex showed significant increases in protein and mRNA levels of cPLA(2)-IVA, secretory sPLA(2)-IIA, cyclooxygenase-1 and -2, membrane prostaglandin (PG) synthase-1 and lipoxygenase-12 and -15. Calcium-independent iPLA(2)-VIA and cytosolic PGE(2) synthase were decreased. In addition, interleukin-1ß, tumor necrosis factor-α, glial fibrillary acidic protein and CD11b were increased. AD postmortem brain also showed signs of cellular injury, including decreased synaptophysin and drebrin, pre- and postsynaptic markers. These results indicate that increased AA cascade and inflammatory markers could contribute to AD pathology. Altered brain AA cascade enzymes could be considered therapeutic targets for future drug development.


Assuntos
Doença de Alzheimer/metabolismo , Ácido Araquidônico/metabolismo , Encéfalo/patologia , Mediadores da Inflamação/fisiologia , Sinapses/fisiologia , Transmissão Sináptica/fisiologia , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Doença de Alzheimer/fisiopatologia , Ácido Araquidônico/biossíntese , Biomarcadores/metabolismo , Encéfalo/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vias Neurais/metabolismo , Vias Neurais/patologia , Vias Neurais/fisiopatologia , Neuropeptídeos/metabolismo , Regulação para Cima/fisiologia
8.
Mol Psychiatry ; 15(6): 602-14, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18982003

RESUMO

Agents effective against mania in bipolar disorder are reported to decrease turnover of arachidonic acid (AA) in phospholipids and expression of calcium-dependent AA-selective cytosolic phospholipase A(2) (cPLA(2)) in rat brain. In contrast, fluoxetine, an antidepressant that is reported to switch bipolar depressed patients to mania, increases cPLA(2) expression and AA turnover in rat brain. We therefore hypothesized that antidepressants that increase switching to mania generally increase cPLA(2) and AA turnover in brain. To test this hypothesis, adult male CDF-344 rats were administered imipramine and bupropion, with reported high and low switching rates, respectively, at daily doses of 10 and 30 mg kg(-1) i.p., respectively, or i.p. saline (control) for 21 days. Frontal cortex expression of different PLA(2) enzymes and AA turnover rates in brain when the rats were unanesthetized were measured. Compared with chronic saline, chronic imipramine but not bupropion significantly increased cortex cPLA(2) mRNA activity, protein and phosphorylation, expression of the cPLA(2) transcription factor, activator protein-2alpha (AP-2alpha) and AA turnover in phospholipids. Protein levels of secretory phospholipase A(2), calcium-independent phospholipase A(2), cyclooxygenase (COX)-1 and COX-2 were unchanged, and prostaglandin E(2) was unaffected. These results, taken with prior data on chronic fluoxetine in rats, suggest that antidepressants that increase the switching tendency of bipolar depressed patients to mania do so by increasing AA recycling and metabolism in brain. Mania in bipolar disorder thus may involve upregulated brain AA metabolism.


Assuntos
Ácido Araquidônico/metabolismo , Transtorno Bipolar/diagnóstico , Transtorno Bipolar/metabolismo , Bupropiona/farmacologia , Lobo Frontal/efeitos dos fármacos , Imipramina/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Bupropiona/administração & dosagem , Ciclo-Oxigenase 1/biossíntese , Ciclo-Oxigenase 2/biossíntese , Dinoprostona/biossíntese , Esquema de Medicação , Lobo Frontal/metabolismo , Humanos , Imipramina/administração & dosagem , Masculino , Fosfolipases A2 Independentes de Cálcio/biossíntese , Fosfolipases A2 Citosólicas/biossíntese , Fosforilação/efeitos dos fármacos , Ratos , Fator de Transcrição AP-2/biossíntese , Regulação para Cima/efeitos dos fármacos
9.
Mol Psychiatry ; 15(4): 384-92, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19488045

RESUMO

Reports of cognitive decline, symptom worsening and brain atrophy in bipolar disorder (BD) suggest that the disease progresses over time. The worsening neuropathology may involve excitotoxicity and neuroinflammation. We determined protein and mRNA levels of excitotoxicity and neuroinflammatory markers in postmortem frontal cortex from 10 BD patients and 10 age-matched controls. The brain tissue was matched for age, postmortem interval and pH. The results indicated statistically significant lower protein and mRNA levels of the N-methyl-D-aspartate receptors, NR-1 and NR-3A, but significantly higher protein and mRNA levels of interleukin (IL)-1beta, the IL-1 receptor (IL-1R), myeloid differentiation factor 88, nuclear factor-kappa B subunits, and astroglial and microglial markers (glial fibrillary acidic protein, inducible nitric oxide synthase, c-fos and CD11b) in postmortem frontal cortex from BD compared with control subjects. There was no significant difference in mRNA levels of tumor necrosis factor alpha or neuronal nitric oxide synthase in the same region. These data show the presence of excitotoxicity and neuroinflammation in BD frontal cortex, with particular activation of the IL-R cascade. The changes may account for reported evidence of disease progression in BD and be a target for future therapy.


Assuntos
Transtorno Bipolar/patologia , Lobo Frontal/metabolismo , Regulação da Expressão Gênica/fisiologia , Mediadores da Inflamação/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Adulto , Antígeno CD11b/metabolismo , Estudos de Casos e Controles , Feminino , Humanos , Interleucina-1beta/genética , Interleucina-1beta/metabolismo , Masculino , Pessoa de Meia-Idade , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Mudanças Depois da Morte , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , RNA Mensageiro/metabolismo , Receptores de Interleucina-1/genética , Receptores de Interleucina-1/metabolismo , Receptores de N-Metil-D-Aspartato/classificação , Receptores de N-Metil-D-Aspartato/genética , Estatística como Assunto
10.
J Neural Transm (Vienna) ; 116(11): 1543-9, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19756369

RESUMO

Lithium, which is approved for treating patients with bipolar disorder, is reported to inhibit 3'(2')-phosphoadenosine-5'-phosphate (PAP) phosphatase activity. In yeast, deletion of PAP phosphatase results in elevated PAP levels and in inhibition of sulfation and of growth. The effect of lithium on PAP phosphatase is remarkable for the low Ki (approximately 0.2 mM), suggesting that this system would be almost completely shut down in vivo with therapeutic levels of 1 mM lithium, thereby elevating PAP levels. To test the hypothesis that lithium inhibition of PAP phosphatase is pharmacologically relevant to bipolar disorder, we fed rats LiCl for 6 weeks, and assayed brain PAP levels after subjecting the brain to high-energy microwaving. We also measured PAP phosphatase mRNA and protein levels in frozen brain tissue of lithium-treated mice. Brain adenosine phosphates were extracted by trichloroacetic acid and assayed by HPLC with a gradient system of two phases. PAP phosphatase mRNA was measured by RT-PCR, and PAP phosphatase protein was measured by Western blotting. Brain PAP levels were below detection limit of 2 nmol/g wet weight, even following lithium treatment. Lithium treatment also did not significantly change brain PAP phosphatase mRNA or protein levels. These results question the relevance of PAP phosphatase to the therapeutic mechanism of lithium. A statistically significant 25% reduced brain ADP/ATP ratio was found following lithium treatment in line with lithium's suggested neuroprotective effects.


Assuntos
Transtorno Bipolar/tratamento farmacológico , Transtorno Bipolar/enzimologia , Encéfalo/efeitos dos fármacos , Encéfalo/enzimologia , Compostos de Lítio/farmacologia , Monoéster Fosfórico Hidrolases/metabolismo , Nucleotídeos de Adenina/metabolismo , Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Antimaníacos/farmacologia , Antimaníacos/uso terapêutico , Transtorno Bipolar/fisiopatologia , Encéfalo/fisiopatologia , Química Encefálica/efeitos dos fármacos , Química Encefálica/fisiologia , Cloreto de Lítio/farmacologia , Compostos de Lítio/uso terapêutico , Masculino , Fármacos Neuroprotetores/farmacologia , Monoéster Fosfórico Hidrolases/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Endogâmicos F344
11.
Klin Med (Mosk) ; 86(5): 28-30, 2008.
Artigo em Russo | MEDLINE | ID: mdl-18589713

RESUMO

Morphofunctional state of gastric mucous tunic and neuroendocrine cells, and clinical indices at various stages of gastric and duodenal ulcer disease was studied. It was shown, that in clinico-endoscopic remission stage of disease intensity of pathogenetic mechanisms of some neuroimmune-endocrine and clinical indices remained.


Assuntos
Úlcera Duodenal/patologia , Gastrinas/metabolismo , Qualidade de Vida , Serotonina/metabolismo , Somatostatina/metabolismo , Úlcera Gástrica/patologia , Adulto , Biomarcadores/metabolismo , Progressão da Doença , Úlcera Duodenal/metabolismo , Úlcera Duodenal/psicologia , Endoscopia Gastrointestinal , Feminino , Determinação da Acidez Gástrica , Mucosa Gástrica/metabolismo , Mucosa Gástrica/patologia , Humanos , Mucosa Intestinal/metabolismo , Mucosa Intestinal/patologia , Masculino , Prognóstico , Índice de Gravidade de Doença , Úlcera Gástrica/metabolismo , Úlcera Gástrica/psicologia
12.
Klin Med (Mosk) ; 84(7): 32-5, 2006.
Artigo em Russo | MEDLINE | ID: mdl-16924798

RESUMO

Changes in the antral gastric mucosa of patients with doudenal ulcer after a long-term administration of antisecretory agents were studied. The subjects were five patients with a different duration of the disease. The methods applied included light and electron microscopy of tissue samplings taken from the antral part of the stomach during the periods of exacerbation and remission. In addition to well-known morphological changes, cellular principalis not typical of antral gastric mucosa were found in one patient during exacerbation and remission periods.


Assuntos
Úlcera Duodenal/tratamento farmacológico , Ácido Gástrico/metabolismo , Mucosa Gástrica/ultraestrutura , Antagonistas dos Receptores H2 da Histamina/uso terapêutico , Antro Pilórico/patologia , Adolescente , Idoso , Biópsia , Úlcera Duodenal/metabolismo , Úlcera Duodenal/patologia , Endoscopia Gastrointestinal , Feminino , Seguimentos , Mucosa Gástrica/efeitos dos fármacos , Humanos , Masculino , Microscopia Eletrônica , Pessoa de Meia-Idade , Antro Pilórico/efeitos dos fármacos , Antro Pilórico/metabolismo , Índice de Gravidade de Doença , Resultado do Tratamento
13.
Klin Med (Mosk) ; 84(11): 30-6, 2006.
Artigo em Russo | MEDLINE | ID: mdl-17243607

RESUMO

The purpose of the study was to evaluate the clinical effectiveness of melatonin (melaxen, Unipharm, USA), and its influence on the ultrastructural and histological features on the colon mucosa (CM) in patients with irritable bowel syndrome (IBS) corresponding to Rome criteria II. Twenty-one patients with IBS were examined before and after the end of the therapy (one month upon the beginning of treatment). All the patients had non-specific morphological changes in the CM, which were more pronounced during exacerbation and less significant during remission. The study showed that in terms of stool normalization and sleep improvement in IBS patients the combination of basic therapy and melaxen was more effective than either the combination of basic therapy and psychotropic drugs or basic therapy alone. Basic therapy plus melaxen is comparable in its effects to basic therapy plus psychotropic drugs in terms of coping with pain syndrome and dyspeptic syndrome in IBS patients, the normalization of their mental status and life quality improvement. The treatment of IBS with melaxen proved to be more effective than other therapies, which was proved by histological and electron microscopic studies of the CM.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Síndrome do Intestino Irritável/tratamento farmacológico , Síndrome do Intestino Irritável/patologia , Melatonina/uso terapêutico , Sigmoidoscopia/métodos , Adolescente , Adulto , Biópsia , Colo/efeitos dos fármacos , Colo/patologia , Feminino , Seguimentos , Humanos , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/ultraestrutura , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Resultado do Tratamento
14.
Ter Arkh ; 75(2): 10-4, 2003.
Artigo em Russo | MEDLINE | ID: mdl-12685381

RESUMO

AIM: To study ultrastructural condition of the cels in antral gastric mucosa in patients with duodenal ulcer on melatonin treatment. MATERIAL AND METHODS: Electron microscopy was made of biopsy specimens of antral stomach mucosa obtained from 14 patients with duodenal ulcer (DU) in exacerbation and in clinicoendoscopic remission after therapy with proton pump blockers (group 1) and after this therapy combined mth melatonin (group 2). RESULTS: In patients of group 2 there was an increased number of differentiated cover and principal cells, moderately differentiated parietal cells predominated. CONCLUSION: Melatonin is one of the drugs potentiating trophic processes in gastric mucosa.


Assuntos
Úlcera Duodenal/tratamento farmacológico , Mucosa Gástrica/ultraestrutura , Melatonina/uso terapêutico , Antro Pilórico/ultraestrutura , Adulto , Úlcera Duodenal/patologia , Feminino , Mucosa Gástrica/patologia , Humanos , Masculino , Microscopia Eletrônica , Antro Pilórico/patologia
15.
Neurochem Res ; 27(12): 1641-7, 2002 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-12515317

RESUMO

Until recently, brain phospholipid metabolism was thought to consume only 2% of the ATP consumed by the mammalian brain as a whole. In this paper, however, we calculate that 1.4% of total brain ATP consumption is consumed for the de novo synthesis of ether phospholipids and that another 5% is allocated to the phosphatidylinositide cycle. When added to previous estimates that fatty acid recycling within brain phospholipids and maintenance of membrane lipid asymmetries of acidic phospholipids consume, respectively, 5% and 8% of net brain ATP consumption, it appears that phospholipid metabolism can consume up to 20% of net brain ATP consumption. This new estimate is consistent with recent evidence that phospholipids actively participate in brain signaling and membrane remodeling, among other processes.


Assuntos
Encéfalo/metabolismo , Metabolismo Energético , Fosfolipídeos/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Humanos , Fosforilação , Ratos
16.
Mol Cell Biochem ; 221(1-2): 3-10, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11506183

RESUMO

Rat liver mitochondria respond to changes in energy demand by modulating the amount of RNA synthesized. Coupled rat liver mitochondria were used to determine the relationship between mitochondrial respiration, ATP levels, and mitochondrial transcription. This system included oxidizable substrates (malate and glutamate) and constituents that could support both mitochondrial respiration and transcription. The respiratory inhibitor rotenone, phosphorylation inhibitor oligomycin, and the uncoupler of oxidative phosphorylation carbonyl-cyanide p-triflouromethoxyphehylhydrazone inhibited RNA synthesis. Addition of ADP stimulated mitochondrial transcription and peak RNA synthesis was observed at 1-2 mM ADP. At ADP concentrations above 2 mM, RNA synthesis decreased. These results demonstrate that mitochondrial transcription is tightly coupled to ATP levels.


Assuntos
Trifosfato de Adenosina/biossíntese , Mitocôndrias Hepáticas/metabolismo , RNA/biossíntese , Ativação Transcricional , Difosfato de Adenosina/farmacologia , Animais , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/farmacologia , Respiração Celular , Cromatografia Líquida de Alta Pressão , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Oligomicinas/farmacologia , Consumo de Oxigênio , Fosforilação/efeitos dos fármacos , RNA Mensageiro/biossíntese , RNA Mitocondrial , Ratos , Rotenona/farmacologia , Fatores de Tempo , Transcrição Gênica/efeitos dos fármacos , Desacopladores/farmacologia
17.
Neuroreport ; 12(4): 721-4, 2001 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-11277571

RESUMO

Aluminum (Al) has been implicated in several neurological diseases including dialysis dementia and Alzheimer's disease (AD). One possible mechanism of Al neurotoxicity could involve alteration of mitochondrial gene expression. We exposed PC12 cells to 0.1-100 microM AlCl3 for 6h at pH 7.4. Internalized Al, measured by atomic absorption spectrometry, was linearly proportional to the extracellular Al concentration. Northern blot analyses showed that cytochrome c oxidase subunit III (COX III) mRNA was significantly reduced by 70% after addition of 1 microM AlCl3. Higher concentrations of AlCl3 did not show a significant further effect. These results suggest that Al neurotoxicity involves a specific impairment of cytochrome c oxidase.


Assuntos
Compostos de Alumínio/toxicidade , Adstringentes/toxicidade , Cloretos/toxicidade , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias/enzimologia , Neurônios/efeitos dos fármacos , Cloreto de Alumínio , Compostos de Alumínio/farmacocinética , Doença de Alzheimer/metabolismo , Animais , Adstringentes/farmacocinética , Sobrevivência Celular/efeitos dos fármacos , Cloretos/farmacocinética , Relação Dose-Resposta a Droga , Complexo I de Transporte de Elétrons , Complexo IV da Cadeia de Transporte de Elétrons/genética , Ativação Enzimática/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , NADH NADPH Oxirredutases/genética , Neurônios/citologia , Células PC12 , RNA Mensageiro/análise , RNA Ribossômico/genética , Ratos
18.
Expert Opin Investig Drugs ; 10(10): 1809-18, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11772287

RESUMO

The blood-brain barrier (BBB) to water-soluble drugs and macromolecules can be opened in vivo by infusing a hypertonic solution of arabinose or mannitol into the carotid artery for 30 sec. Opening involves widening of tight junctions between endothelial cells of the cerebrovasculature and is mediated by endothelial cell shrinkage, vascular dilatation associated with removal of water from brain, and modulation of the contractile state of the endothelial cytoskeleton and junctional proteins by increased intracellular calcium. A 10-fold increase in BBB permeability to intravascular substances, lasting about 10 min following osmotic exposure, reflects both increased diffusion and bulk fluid flow from blood into brain. Furthermore, recent evidence indicates that the duration of peak BBB opening can be extended beyond 30 min, by pre-treatment with a Na(+)/Ca(2+) channel blocker. In experimental animals, the osmotic method has been used to grant wide access to brain of water-soluble drugs, peptides, antibodies, boron compounds for neutron capture therapy, viral vectors for gene therapy and enzymes. Ongoing multi-centre clinical studies suggest that the method, when used with intra-arterially administered anticancer drugs, can prolong survival in patients with malignant brain tumours, with minimal morbidity. However, controlled clinical trials are critical to see if the osmotic procedure with intra-arterial drugs enhances survival in brain tumour patients compared with intra-arterial drug alone.


Assuntos
Antineoplásicos/farmacocinética , Antineoplásicos/uso terapêutico , Barreira Hematoencefálica/efeitos dos fármacos , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/metabolismo , Ensaios Clínicos como Assunto , Humanos , Pressão Osmótica
19.
Mitochondrion ; 1(2): 141-50, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16120274

RESUMO

Regulation of expression of mitochondrial DNA- (mtDNA-) encoded genes of oxidative phosphorylation can occur rapidly in neural cells subjected to a variety of physiological and pathological conditions. However, the intracellular signal(s) involved in regulating these processes remain unknown. Using mtDNA-encoded cytochrome oxidase subunit III (COX III), we show that its mRNA expression in a differentiated rat pheochromocytoma cell line PC12S is decreased by chronic exposure to agents that increase intracellular sodium. Treatment of differentiated PC12S cells either with ouabain, an inhibitor of Na/K-ATPase, or with monensin, a sodium ionophore, decreased the steady-state levels of COX III mRNA by 50%, 3-4 h after addition of the drugs. No significant reduction in mtDNA-encoded 12S rRNA or nuclear DNA-encoded beta-actin mRNA were observed. Removal of the drugs restored the normal levels of COX III mRNA. Determination of half-lives of COX III mRNA, 12S rRNA, and beta-actin mRNA revealed a selective decrease in the half-life of COX III mRNA from 3.3 h in control cells to 1.6 h in ouabain-treated cells, and to 1 h in monensin-treated cells. These results suggest the existence of a mechanism of posttranscriptional regulation of mitochondrial gene expression that is independent of the energetic status of the cell and may operate under pathological conditions.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA