RESUMEN
The quantitative autoradiographic method with L-(35S)methionine was used to determine the effects of 1-acute (4h) and 2-chronic (14 days) immobilization stress followed by one week of recovery. Acute stress induced a significant decrease in methionine incorporation into proteins in 17 of the 35 brain structures examined (mean effect: -22%), and a significant increase in the prepositus hypoglossal nucleus (+23%). Chronic stress induced a significant decrease in methionine incorporation into proteins in 8 of the 35 structures analyzed. Only 4 structures were similarly affected in both these conditions. Our results indicate that stress-induced specific molecular changes in brain are also associated with changes in more general molecular components of cellular metabolism.
Asunto(s)
Química Encefálica/fisiología , Proteínas del Tejido Nervioso/biosíntesis , Estrés Psicológico/metabolismo , Enfermedad Aguda , Animales , Autorradiografía , Peso Corporal/fisiología , Enfermedad Crónica , Corticosterona/sangre , Inmovilización , Masculino , Metionina/sangre , Metionina/metabolismo , Tamaño de los Órganos/fisiología , Ratas , Ratas Sprague-Dawley , Radioisótopos de AzufreRESUMEN
The autoradiographic method with [L-35S]methionine was used to determine the effects of a 2 h acute immobilization stress followed by a 4 h recovery on local rates of protein synthesis in the adult rat brain. Methionine incorporation into proteins was significantly increased (from 17 to 86%) in 37 out of the 39 analyzed brain structures. These results show that the stress-induced activation of the overall rate of brain protein synthesis may persist for at least 4 h after cessation of the stimulus even though the stress-related physiological variables have returned to basal levels. They suggest that increased protein synthesis may play a key role in the molecular events which lead to the neuronal plastic changes following an acute stress.
Asunto(s)
Encéfalo/metabolismo , Inmovilización , Proteínas del Tejido Nervioso/biosíntesis , Estrés Fisiológico/metabolismo , Enfermedad Aguda , Animales , Autorradiografía , Masculino , Metionina/metabolismo , Ratas , Ratas Sprague-Dawley , Distribución TisularRESUMEN
The autoradiographic method with L-[35S]methionine was used to examine the effect of acute administration of L-triiodothyronine on local rates of brain protein synthesis in free-moving adult rats. Triiodothyronine was given intraperitoneally at doses of 12.5 or 25 micrograms kg-1. It did not modify the rate of plasma methionine incorporation in the 40 brain regions examined, despite a 4- to 8-fold increase of plasma free triiodothyronine levels. Biochemical analysis confirmed that triiodothyronine (25 micrograms kg-1) had no apparent effect on the overall rate of protein synthesis in the brain as a whole. These results suggest that changes in the circulating levels of thyroid hormones do not exert a general and direct metabolic effect in brain of intact adult rats.
Asunto(s)
Encéfalo/metabolismo , Metionina/metabolismo , Proteínas/metabolismo , Triyodotironina/sangre , Animales , Encéfalo/fisiología , Corteza Cerebral/metabolismo , Diencéfalo/metabolismo , Hipocampo/metabolismo , Masculino , Ratas , Ratas Sprague-Dawley , Hormonas Tiroideas/sangre , Hormonas Tiroideas/fisiología , Triyodotironina/fisiologíaRESUMEN
Regional brain protein synthesis was evaluated with positron emission tomography (PET) and L-(S-[11C]methyl)methionine ([11C]MET) in depressive patients, before and 3 h after an electroconvulsive shock (ECS), when energy supply is restored, and in healthy volunteers. Depressive patients presented apparent lower protein synthesis than normals, in agreement with known reduction of cerebral activity. In contrast, ECS resulted in a significant increase (56%, P < 0.05) in global cortical protein synthesis. This paradoxical hyperactivation of cellular protein metabolism in response to seizures and the fact that synaptic activity is further reduced after electroconvulsive therapy (ECT), may provide new insights for understanding the mechanism of action of ECT.
Asunto(s)
Encéfalo/metabolismo , Encéfalo/fisiología , Terapia Electroconvulsiva , Adulto , Presión Sanguínea , Temperatura Corporal , Radioisótopos de Carbono , Depresión/terapia , Femenino , Frecuencia Cardíaca , Humanos , Masculino , Metionina/sangre , Metionina/metabolismo , Persona de Mediana Edad , Proteínas del Tejido Nervioso/metabolismo , Tomografía Computarizada de EmisiónAsunto(s)
Antidepresivos/administración & dosificación , Trastorno Depresivo/tratamiento farmacológico , Antidepresivos/efectos adversos , Ensayos Clínicos como Asunto , Trastorno Depresivo/psicología , Esquema de Medicación , Humanos , Cuidados a Largo Plazo , Recurrencia , Resultado del TratamientoRESUMEN
The authors found a significant statistical correlation (linear and Spearman) between erythrocyte sedimentation rate (ESR), plasma fibrinogen level, alpha-2-globulins level, platelets count, anemia and age, in 1 000 patients admitted to the Hôtel-Dieu of Marseille. The high degree of partial correlations obtained, confirmed that a direct and independent relationship exists between ESR-fibrinogen, ESR - alpha-2-globulin, fibrinogen - alpha-2-globulin. Determinations of plasma fibrinogen and alpha-2-globulin levels are they still useful in the survey of inflammatory diseases when ESR can be easily determined?