RESUMEN
This review is designed to analyse current views of physicians representing different fields of medicine (psychoanalysis, pathological anatomy, psychiatry, etc.) on the problem of psychosomatic diseases with reference to its history, past and present concepts, etiopathogenetic mechanisms of these conditions. The authors propose to use the results of analysis as a basis for considering psychosomatic diseases as a singular etiopathogenetic entity resulting from dysregulation of rhythm-organizing structures.
Asunto(s)
Enfermedades Gastrointestinales , Trastornos Psicofisiológicos , Medicina Psicosomática , Actitud del Personal de Salud , Enfermedades Gastrointestinales/diagnóstico , Enfermedades Gastrointestinales/etiología , Enfermedades Gastrointestinales/fisiopatología , Historia del Siglo XX , Humanos , Psicoanálisis/historia , Trastornos Psicofisiológicos/diagnóstico , Trastornos Psicofisiológicos/etiología , Trastornos Psicofisiológicos/fisiopatología , Trastornos Psicofisiológicos/psicología , Psicofisiología , Medicina Psicosomática/historia , Medicina Psicosomática/métodosAsunto(s)
Trastornos Cronobiológicos , Ritmo Circadiano/fisiología , Melatonina , Periodicidad , Antioxidantes/metabolismo , Antioxidantes/uso terapéutico , Disciplina de Cronobiología , Trastornos Cronobiológicos/tratamiento farmacológico , Trastornos Cronobiológicos/etiología , Trastornos Cronobiológicos/metabolismo , Trastornos Cronobiológicos/fisiopatología , Cronoterapia/métodos , Humanos , Melatonina/metabolismo , Melatonina/uso terapéuticoRESUMEN
Alzheimer's disease (AD) and bipolar disorder (BD) are progressive brain disorders. Upregulated mRNA and protein levels of neuroinflammatory and arachidonic acid (AA) markers with loss of synaptic markers (synaptophysin and drebrin) have been reported in brain tissue from AD and BD patients. We hypothesized that some of these changes are associated with epigenetic modifications of relevant genes. To test this, we measured gene-specific CpG methylation, global DNA methylation and histone modifications in postmortem frontal cortex from BD (n=10) and AD (n=10) patients and respective age-matched controls (10 per group). AD and BD brains showed several epigenetic similarities, including global DNA hypermethylation, and histone H3 phosphorylation. These changes were associated with hypo- and hypermethylation of CpG islands in cyclooxygenase-2 and brain-derived neurotrophic factor promoter regions, respectively. Only the AD brain showed hyper- and hypomethylated CpG islands in promoter regions for cAMP response element-binding protein and nuclear transcription factor kappa B genes, respectively. Only the BD brain demonstrated increased global histone H3 acetylation and hypermethylation of the promotor region for the drebrin-like protein gene. There was no significant epigenetic modification for 12-lipooxygenase or p450 epoxygenase in either illness. Many observed epigenetic changes were inversely related to respective changes in mRNA and protein levels. These epigenetic modifications involving neuroinflammatory, AA cascade and synaptic markers may contribute to progression in AD and BD and identify new targets for drug development.
Asunto(s)
Enfermedad de Alzheimer/genética , Ácido Araquidónico/metabolismo , Trastorno Bipolar/genética , Metilación de ADN/genética , Epigénesis Genética , Lóbulo Frontal/metabolismo , Regiones Promotoras Genéticas/genética , Anciano , Enfermedad de Alzheimer/fisiopatología , Trastorno Bipolar/fisiopatología , Islas de CpG/genética , Islas de CpG/fisiología , Metilación de ADN/fisiología , Femenino , Histonas/metabolismo , Humanos , Masculino , Persona de Mediana Edad , Regiones Promotoras Genéticas/fisiologíaRESUMEN
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.
Asunto(s)
Ácido Araquidónico/metabolismo , Trastorno Bipolar/diagnóstico , Trastorno Bipolar/metabolismo , Bupropión/farmacología , Lóbulo Frontal/efectos de los fármacos , Imipramina/farmacología , Transducción de Señal/efectos de los fármacos , Animales , Bupropión/administración & dosificación , Ciclooxigenasa 1/biosíntesis , Ciclooxigenasa 2/biosíntesis , Dinoprostona/biosíntesis , Esquema de Medicación , Lóbulo Frontal/metabolismo , Humanos , Imipramina/administración & dosificación , Masculino , Fosfolipasas A2 Calcio-Independiente/biosíntesis , Fosfolipasas A2 Citosólicas/biosíntesis , Fosforilación/efectos de los fármacos , Ratas , Factor de Transcripción AP-2/biosíntesis , Regulación hacia Arriba/efectos de los fármacosRESUMEN
Non-medicamenous methods for the treatment of metabolic syndrome (MS) are discussed. Diagnosis of MS is a priority problem of modern medicine and healthcare because of its important role in pathogenesis of type 2 diabetes, essential hypertension, and atherosclerosis complicated by coronary heart disease, i.e. major causes of mortality worldwide. Non-medicamentous treatment permits to diminish the total amount of pharmaceuticals prescribed to the patients and to improve the overall result of drug therapy. These methods include remedial gymnastics, physiotherapy, reflexotherapy, balneological treatment, and psychotherapy. Different modalities of non-medicamentous therapy are considered with special reference to the methods for lowering body weight as an earliest and most dangerous manifestation of MS. Indications and contraindications to the use of concrete therapeutic modalities are described.
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Terapia por Ejercicio/métodos , Síndrome Metabólico/terapia , Modalidades de Fisioterapia , Psicoterapia/métodos , Reflejoterapia/métodos , Humanos , Resultado del TratamientoRESUMEN
Decreased docosahexaenoic acid (DHA) and brain-derived neurotrophic factor (BDNF) have been implicated in bipolar disorder. It also has been reported that dietary deprivation of n-3 polyunsaturated fatty acids (PUFAs) for 15 weeks in rats, increased their depression and aggression scores. Here, we show that n-3 PUFA deprivation for 15 weeks decreased the frontal cortex DHA level and reduced frontal cortex BDNF expression, cAMP response element binding protein (CREB) transcription factor activity and p38 mitogen-activated protein kinase (MAPK) activity. Activities of other CREB activating protein kinases were not significantly changed. The addition of DHA to rat primary cortical astrocytes in vitro, induced BDNF protein expression and this was blocked by a p38 MAPK inhibitor. DHA's ability to regulate BDNF via a p38 MAPK-dependent mechanism may contribute to its therapeutic efficacy in brain diseases having disordered cell survival and neuroplasticity.
Asunto(s)
Trastorno Bipolar/metabolismo , Factor Neurotrófico Derivado del Encéfalo/metabolismo , Ácidos Grasos Omega-3/farmacología , Lóbulo Frontal/metabolismo , Proteínas Quinasas p38 Activadas por Mitógenos/metabolismo , Animales , Astrocitos/citología , Astrocitos/metabolismo , Factor Neurotrófico Derivado del Encéfalo/genética , Núcleo Celular/enzimología , Células Cultivadas , Proteína de Unión a Elemento de Respuesta al AMP Cíclico/metabolismo , Grasas Insaturadas en la Dieta/farmacología , Ácidos Docosahexaenoicos/metabolismo , Inhibidores Enzimáticos/farmacología , Femenino , Lóbulo Frontal/citología , Lóbulo Frontal/crecimiento & desarrollo , Imidazoles/farmacología , Masculino , Fosforilación , Piridinas/farmacología , ARN Mensajero/metabolismo , Ratas , Ratas Long-Evans , Proteínas Quinasas p38 Activadas por Mitógenos/antagonistas & inhibidoresRESUMEN
The enzymes that regulate the brain arachidonic acid (AA) cascade have been implicated in bipolar disorder and neuroinflammation. Fifteen weeks of dietary n-3 polyunsaturated fatty acid (PUFA) deprivation in rats decreases the concentration of docosahexaenoic acid (DHA) and increases its half-life within the brain. Based on this, we hypothesized that such dietary deprivation would decrease expression of enzymes responsible for the metabolic loss of DHA while increasing expression of those responsible for the metabolism of AA. Fifteen weeks of n-3 PUFA deprivation significantly decreased the activity, protein and mRNA expression of the DHA regulatory phospholipase A2 (PLA2), calcium-independent iPLA2, in rat frontal cortex. In contrast the activities, protein and mRNA levels of the AA selective calcium-dependent cytosolic phospholipase (cPLA2) and secretory sPLA2 were increased. Cyclooxygenase (COX)-1 protein but not mRNA was decreased in the n-3 PUFA-deprived rats whereas COX-2 protein and mRNA were increased. This study suggests that n-3 PUFA deprivation increases the half-live of brain DHA by downregulating iPLA2. The finding that n-3 PUFA deprivation increases cPLA2, sPLA2 and COX-2 is opposite to what has been reported after chronic administration of anti-manic agents to rats and suggests that n-3 PUFA deprivation may increase susceptibility to bipolar disorder.
Asunto(s)
Ácido Araquidónico/metabolismo , Ciclooxigenasa 1/genética , Ácidos Docosahexaenoicos/metabolismo , Ácidos Grasos Omega-3/farmacología , Lóbulo Frontal/enzimología , Animales , Ciclooxigenasa 1/metabolismo , Grasas de la Dieta/farmacología , Activación Enzimática/efectos de los fármacos , Lóbulo Frontal/efectos de los fármacos , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Fosfolipasas A2 Grupo II , Masculino , Fosfolipasas A/genética , Fosfolipasas A/metabolismo , Fosfolipasas A2 , ARN Mensajero/metabolismo , Ratas , Ratas Long-EvansRESUMEN
Chronic lithium and carbamazepine, which are effective against mania in bipolar disorder, decrease the activity of cytosolic phospholipase A(2) (cPLA(2)) and the turnover rate of arachidonic acid in phospholipids in rat brain. Assuming that stages of bipolar disorder are related to brain arachidonic acid metabolism, we hypothesized that drugs effective in depression would increase cPLA(2) activity. To test this hypothesis, adult male CDF-344 rats were administered fluoxetine (10 mg/kg intraperitoneally (i.p.) or saline (control) (i.p.) chronically for 21 days. Frontal cortex cPLA(2) protein, phosphorylated cPLA(2), activity and mRNA levels were increased after chronic fluoxetine. Transcription factors (activator protein-1, activator protein-2, glucocorticoid response element, polyoma enhancer element-3 and nuclear factor-kappa B) that are known to regulate cPLA(2) gene expression were not significantly changed by chronic fluoxetine, but nuclear AU-rich element/poly(U)-binding/degradation factor-1 RNA-stabilizing protein was increased significantly. The results suggest that chronic fluoxetine increases brain cPLA(2) gene expression post-transcriptionally by increasing cPLA(2) mRNA stabilization. Chronic fluoxetine's effect on cPLA(2) expression was opposite to the effect reported with chronic lithium or carbamazepine administration, and may be part of fluoxetine's mode of action.
Asunto(s)
Fluoxetina/farmacología , Lóbulo Frontal/enzimología , Fosfolipasas A/genética , Complejo 2 de Proteína Adaptadora/metabolismo , Animales , Citosol/enzimología , Lóbulo Frontal/efectos de los fármacos , Expresión Génica/efectos de los fármacos , Ribonucleoproteína Nuclear Heterogénea D0 , Ribonucleoproteína Heterogénea-Nuclear Grupo D/metabolismo , Masculino , Fosfolipasas A/biosíntesis , Fosfolipasas A2 , Fosforilación , ARN Mensajero/metabolismo , Ratas , Factor de Transcripción AP-1/metabolismo , Factores de Transcripción/metabolismo , Regulación hacia ArribaRESUMEN
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.
Asunto(s)
Adyuvantes Inmunológicos/uso terapéutico , Síndrome del Colon Irritable/tratamiento farmacológico , Síndrome del Colon Irritable/patología , Melatonina/uso terapéutico , Sigmoidoscopía/métodos , Adolescente , Adulto , Biopsia , Colon/efectos de los fármacos , Colon/patología , Femenino , Estudios de Seguimiento , Humanos , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/ultraestructura , Masculino , Persona de Mediana Edad , Calidad de Vida , Resultado del TratamientoRESUMEN
Polyunsaturated fatty acids (PUFAs) are critical to nervous system function and structure, but their rates of incorporation from plasma into brain have not been evaluated. In the adult rat, calculations based on our model show that at least 3;-5% of esterified brain arachidonic acid (AA) and 2;-8% of esterified brain docosahexaenoic acid (DHA) are replaced daily by unesterified PUFAs in plasma. These rates, when related to unlabeled brain PUFA composition, give half-lives of 1-2 weeks for plasma-brain exchange of AA and DHA. In the human brain, the arachidonate replacement rate is 0.3% per day. Although unesterified plasma PUFA concentrations are low, their rates of incorporation into brain are sufficient to compensate for metabolic and efflux losses, so that PUFA transport from plasma into brain as a component of a lipoprotein is unnecessary. Dietary supplementation, by altering plasma unesterified PUFA concentrations, can regulate brain PUFA content and may help to treat brain diseases involving PUFA imbalance.
Asunto(s)
Encéfalo/metabolismo , Ácidos Grasos Insaturados/metabolismo , Animales , Ácido Araquidónico/sangre , Ácido Araquidónico/metabolismo , Encéfalo/diagnóstico por imagen , Grasas Insaturadas en la Dieta , Ácidos Docosahexaenoicos/sangre , Ácidos Docosahexaenoicos/metabolismo , Ácidos Grasos Insaturados/administración & dosificación , Ácidos Grasos Insaturados/sangre , Ácidos Grasos Insaturados/química , Humanos , Cinética , Masculino , Modelos Biológicos , Ratas , Tomografía Computarizada de EmisiónRESUMEN
We applied our in vivo fatty acid method to examine concentrations, incorporation, and turnover rates of docosahexaenoic acid (22:6 n-3) in brains of rats subject to a dietary deficiency of alpha-linolenic acid (18:3 n-3) for three generations. Adult deficient and adequate rats of the F3 generation were infused intravenously with [4, 5-(3)H]docosahexaenoic acid over 5 min, after which brain uptake and distribution of tracer were measured. Before infusion, the plasma 22:6 n-3 level was 0.2 nmol ml(-1) in 18:3 n-3-deficient compared with 10.6 nmol ml(-1) in control rats. Brain unesterified 22:6 n-3 was not detectable, whereas docosahexaenoyl-CoA content was reduced by 95%, and 22:6 n-3 content in different phospholipid classes was reduced by 83-88% in deficient rats. Neither plasma or brain arachidonic acid (20:4 n-6) level was significantly changed with diet. Docosapentaenoic acid (22:5 n-6) reciprocally replaced 22:6 n-3 in brain phospholipids. Calculations using operational equations from our model indicated that 22:6 n-3 incorporation from plasma into brain was reduced 40-fold by 18:3 n-3 deficiency. Recycling of 22:6 n-3 due to deacylation-reacylation within phospholipids was reduced by 30-70% with the deficient diet, but animals nevertheless continued to produce 22:6 n-3 and docosahexaenoyl-CoA for brain function. We propose that functional brain effects of n-3 deficiency reflect altered ratios of n-6 to n-3 fatty acids.
Asunto(s)
Acilcoenzima A/metabolismo , Encéfalo/metabolismo , Dieta , Ácidos Docosahexaenoicos/metabolismo , Ácido alfa-Linolénico/deficiencia , Acilación , Animales , Peso Corporal , Ácidos Docosahexaenoicos/administración & dosificación , Ácidos Docosahexaenoicos/farmacocinética , Ácidos Grasos no Esterificados/sangre , Ácidos Grasos Omega-3/sangre , Femenino , Infusiones Intravenosas , Masculino , Fosfolípidos/metabolismo , Ratas , Ratas Long-Evans , Tritio , Ácido alfa-Linolénico/metabolismoRESUMEN
Phospholipid composition (mol %) and levels (nmol/mg protein) were determined in postmortem frontal cortical and cerebellar gray matter from older Down Syndrome (DS) patients (age range 38-68 years) and from control subjects. Neither DS nor control tissue exhibited any age-dependent alteration in phospholipid composition or levels. Total phospholipid content was significantly reduced approximately 20% in DS frontal cortex and cerebellum relative to these regions in control tissue. Individual phospholipid levels were also reduced in DS frontal cortex and cerebellum, including a specific 37% decrease in phosphatidylinositol (PtdIns) and a nearly 35% decrease in ethanolamine plasmalogen. Because of the large decrease in phospholipid content in DS brain, the cholesterol/phospholipid ratio was calculated for each group. There was no significant difference in this ratio between groups, indicative of compensatory changes to keep the cholesterol/phospholipid ratio constant. Despite the large changes in DS brain phospholipid levels, significant changes in composition were limited to a 18% decrease in PtdIns mol % and a 22% increase in the mol % of sphingomyelin. These results suggest either a decrease in membrane phospholipids due to a loss of dendrites and dendritic spines, or a general defect in brain lipid metabolism in older DS subjects. The proportionally greater alterations in PtdIns and PlsEtn levels, indicate that the metabolism of these two phospholipids was affected to a greater extent than the other phospholipids. Further, because these changes are found in both the frontal cortical and cerebellar gray matter, they likely are related to the Down syndrome condition rather than to Alzheimer neuropathology.
Asunto(s)
Cerebelo/metabolismo , Síndrome de Down/metabolismo , Lóbulo Frontal/metabolismo , Fosfolípidos/metabolismo , Adulto , Anciano , Anciano de 80 o más Años , Envejecimiento/metabolismo , Envejecimiento/patología , Cerebelo/patología , Colesterol/metabolismo , Síndrome de Down/patología , Femenino , Lóbulo Frontal/patología , Humanos , Masculino , Persona de Mediana Edad , Fosfatidilcolinas/metabolismo , Fosfatidiletanolaminas/metabolismo , Fosfatidilinositoles/metabolismo , Fosfatidilserinas/metabolismo , Plasmalógenos/metabolismo , Esfingomielinas/metabolismoRESUMEN
myo-Inositol is elevated in the Down syndrome (DS; trisomy 21) brain and may play a role in mental retardation. In the present study, we examined brain regions and peripheral tissues of Ts65Dn mouse, a recently characterized genetic model of DS, for abnormal myo-inositol accumulation. A GC/MS technique was used to quantitate myo-inositol and other polyol species (ribitol, arabitol, xylitol, and 1,5-anhydrosorbitol) in tissues from the Ts65Dn mice and control diploid mice. myo-Inositol was found to be elevated in frontal cortex, hippocampus, and brain stem but not in cerebellum of the Ts65Dn mouse. Among peripheral organs examined, liver and skeletal muscle were found to excessively accumulate myo-inositol. In all tissues, concentrations of polyol internal controls were normal. The Ts65Dn mouse is useful to study the possible effect of elevated myo-inositol on cellular processes.
Asunto(s)
Encéfalo/metabolismo , Síndrome de Down/metabolismo , Inositol/metabolismo , Animales , Tronco Encefálico/metabolismo , Cerebelo/metabolismo , Modelos Animales de Enfermedad , Síndrome de Down/genética , Femenino , Lóbulo Frontal/metabolismo , Hipocampo/metabolismo , Hígado/metabolismo , Masculino , Ratones , Músculo Esquelético/metabolismo , Especificidad de Órganos , Valores de Referencia , Alcoholes del Azúcar/metabolismo , TrisomíaRESUMEN
UNLABELLED: Alzheimer's disease is associated with reductions in resting-state brain metabolism, as measured by PET, progressing with dementia severity. The purpose of this study was to see to what extent brain regions with reduced resting-state metabolic rates in Alzheimer patients could be activated by a passive audiovisual stimulation test and to compare the result with activation in age-matched healthy volunteers. The extent of activation in Alzheimer's disease is considered to reflect the integrity of synaptic function, or inherent viability, and the potential responsiveness of the Alzheimer brain to drug therapy. METHODS: Regional cerebral metabolic rates for glucose (rCMRglc, in mg/ 100 g tissue/min) were measured in the resting state (eyes and ears covered) and during passive audiovisual stimulation (watching a movie) in 15 otherwise healthy Alzheimer patients of differing dementia severity (Mattis Dementia Rating Scale score, 23-128) and in 14 age-matched healthy volunteers (score, 141 +/- 3) using PET with 2 sequential injections of FDG. RESULTS: In the volunteers, audiovisual stimulation caused significant rCMRglc increases in visual and auditory cortical areas but significant decreases in frontal areas. In the mildly demented patients, rCMRglc responses were within 2 SDs of the mean in volunteers. However, the magnitude of the rCMRglc responses during stimulation declined significantly with dementia severity in the right occipitotemporal, right and left occipital association, and left calcarine cortical regions. CONCLUSION: Functional brain responsiveness, evaluated by a passive audiovisual stimulation paradigm with PET, is within normal limits in mildly demented Alzheimer patients but fails with worsening dementia severity. Declining responsiveness may account for the limited success of neurotransmitter replacement therapy in Alzheimer patients with moderate-to-severe dementia.
Asunto(s)
Enfermedad de Alzheimer/diagnóstico por imagen , Encéfalo/metabolismo , Tomografía Computarizada de Emisión , Estimulación Acústica , Anciano , Enfermedad de Alzheimer/fisiopatología , Encéfalo/diagnóstico por imagen , Estudios de Casos y Controles , Femenino , Radioisótopos de Flúor , Fluorodesoxiglucosa F18 , Glucosa/metabolismo , Humanos , Masculino , Estimulación Luminosa , RadiofármacosRESUMEN
OBJECTIVE: This study tested the hypothesis that regional cerebral glucose metabolism during neuronal activation is a more sensitive index of neuronal dysfunction and clinical severity in Alzheimer's disease than is glucose metabolism at rest. METHOD: The subjects were 15 Alzheimer's disease patients with a wide range of Mattis Dementia Rating Scale scores (23-128). By using positron emission tomography, absolute glucose metabolism was measured in the parietal, occipital (visual areas), and temporal (auditory areas) cortical regions during rest (eyes/ears covered) and audiovisual stimulation. RESULTS: In the parietal cortex, glucose metabolism correlated with dementia severity in both conditions. In contrast, in the relatively preserved visual and auditory cortical regions, glucose metabolism predicted dementia severity during stimulation but not at rest. CONCLUSIONS: These findings suggest that regional cerebral glucose metabolism during stimulation is a more sensitive index of the functional/metabolic failure of neuronal systems than is metabolism at rest.
Asunto(s)
Enfermedad de Alzheimer/diagnóstico , Encéfalo/metabolismo , Glucosa/metabolismo , Tomografía Computarizada de Emisión/métodos , Estimulación Acústica , Anciano , Enfermedad de Alzheimer/diagnóstico por imagen , Enfermedad de Alzheimer/fisiopatología , Corteza Auditiva/metabolismo , Encéfalo/diagnóstico por imagen , Encéfalo/fisiopatología , Femenino , Fluorodesoxiglucosa F18 , Humanos , Masculino , Lóbulo Parietal/metabolismo , Estimulación Luminosa , Escalas de Valoración Psiquiátrica/estadística & datos numéricos , Índice de Severidad de la Enfermedad , Corteza Visual/metabolismoRESUMEN
Transient cerebral ischemia (5 min) releases unesterified fatty acids from membrane phospholipids, increasing brain concentrations of fatty acids for up to 1 h following reperfusion. To understand the reported anti-ischemic effect of Ginkgo biloba extract (EGb 761), we monitored its effect on brain fatty acid reincorporation in a gerbil-stroke model. Both common carotid arteries in awake gerbils were occluded for 5 min, followed by 5 min of reperfusion. Animals were infused intravenously with labeled arachidonic (AA) or palmitic acid (Pam), and rates of incorporation of unlabeled fatty acid from the brian acyl-CoA pool were calculated by the model of Robinson et al. (1992), using quantitative autoradiography and biochemical analysis of brain acyl-CoA. Animals were treated for 14 d with 50 or 150 mg/kg/d EGb 761 or vehicle. Ischemia-reperfusion had no effect on the rate of unlabeled Pam incorporation into brain phospholipids from palmitoyl-CoA; this rate also was unaffected by EGb 761. In contrast, ischemia-reperfusion increased the rate of incorporation of unlabeled AA from brain arachidonoyl-CoA by a factor of 2.3-3.3 compared with the control rate; this factor was further augmented to 3.6-5.0 by pretreatment with EGb 761. There is selective reincorporation of AA compared with Pam into brain phospholipids following ischemia. EGb 761 further accelerates AA reincorporation, potentially reducing neurotoxic effects of prolonged exposure of brain to high concentrations of AA and its metabolites.
Asunto(s)
Química Encefálica/efectos de los fármacos , Ácidos Grasos/metabolismo , Ginkgo biloba/química , Ataque Isquémico Transitorio/tratamiento farmacológico , Lípidos de la Membrana/metabolismo , Fármacos Neuroprotectores/farmacología , Fosfolípidos/metabolismo , Extractos Vegetales , Plantas Medicinales , Daño por Reperfusión/prevención & control , Animales , Ácido Araquidónico/metabolismo , Flavonoides , Gerbillinae , Ataque Isquémico Transitorio/metabolismo , Masculino , Fármacos Neuroprotectores/uso terapéutico , Ácido Palmítico/metabolismo , Daño por Reperfusión/metabolismo , VigiliaRESUMEN
We examined regional cerebral metabolic rates for glucose (rCMRglc) and brain incorporation coefficients (k*) of each of three intravenously infused fatty acid radiotracers, [9,10-(3H)]palmitate ([3H]PAM), [1-(14C)]arachidonate ([14C]AA) and [1-(14C)]docosahe-xaenoate ([14C]DHA), in awake rats fully kindled by once-daily electrical stimulation of the left amygdala. Compared with sham-stimulated animals, rCMRglc was increased bilaterally during a seizure, particularly in midbrain-brain stem regions, thalamus and basolateral nucleus of the amygdala. At 24 h and 2 weeks after a seizure, there was no significant change in k* for either [14C]AA or [14C]DHA in any brain region, whereas k* for [3H]PAM at 24 h was increased significantly (by 32-53%) ipsilateral to stimulation in regions of the amygdala and thalamus. Contralateral regions showed no significant change. Two weeks after a seizure, k* for [3H]PAM was increased in the ipsilateral lateral dorsal nucleus of the thalamus. These results argue for membrane remodeling involving phosphatidylcholine in the ipsilateral amygdala and thalamus at the completed phase of amygdala kindling. Remodeling may continue for up to 2 weeks after a seizure during the completed phase.