RESUMO
El factor neurotrófico ciliar (CNTF) es una citokina que tiene efectos tróficos sobre neuronas sensitivas y motoras, ya que modifica su expresión génica y afecta su supervivencia. Este trabajo es una revisión de los antecedentes de los efectos de la aplicación de CNTF en modelos animales de neuropatías degenerativas humanas,que han sugerido que esta citokina tiene potencialidades para convertirse en una herramienta para el tratamiento de pacientes con enfermedad de Huntington. También se describen los efectos de la aplicación experimental de CNTF a pacientes con esclerosis lateral amiotrófica. Entre las técnicas empleadas para aplicar CNTF en modelos animales se encuentran la implantación local de células modificadas genéticamente para secretar CNTF y el uso de vectores para insertar genes en neuronas. Estas técnicas de la biología molecular podrían emplearse como herramientas para el tratamiento preventivo de pacientes susceptibles de desarrollar una patología neurodegenerativa o para recuperar las funciones motoras y cognitivas en pacientes que hayan desarrollado la enfermedad.
Assuntos
Animais , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/terapia , Fator Neurotrófico Ciliar/farmacologia , Fator Neurotrófico Ciliar/uso terapêutico , Doença de Huntington/induzido quimicamente , Receptor do Fator Neutrófico CiliarRESUMO
Background: Glutathione peroxidase (GSHPx) and catalase are two important cellular antioxidant enzymes involved in H2O2 and lipid-peroxide metabolism. Aim: To study the effects of growth, maturation and aging on the activity of these enzymes. Material and methods: GSHPx and catalase specific activities were measured in samples of diaphragm and intercostal muscle of male Sprague-Dawley rats of different ages (21, 50, 70, 180 and 365 days), anesthetised with chloral hydrate (45 mg/100 g ip). Results: The diaphragm and intercostal muscles did not differ in GSHPx activity at 21 days. After that, GSHPx activity increased progressively with age, but following a different pattern, in each muscle, suggesting an increase in enzyme substrates with age. In one year old animals, GSHPx activity was 5 times higher for the diaphragm and 3 times higher for the intercostal muscles, when compared with values observed at 21 days of age. Catalase activity also increased with age in the diaphragm but not in the intercostal muscles. Conclusions: GSHPx activity increases progressively with age in rat respiratory muscles, with a time course that is specific of each muscle. Catalase activity increases with age only in the diaphragm. These results support the hypothesis that antioxidants in respiratory muscles undergo specific regulatory changes with age
Assuntos
Animais , Ratos , Catalase/metabolismo , Glutationa Peroxidase/metabolismo , Músculos Respiratórios/enzimologia , Envelhecimento , Fatores Etários , Ratos Sprague-Dawley/crescimento & desenvolvimentoRESUMO
Background: Although the hamster model of elastase induced emphysema is well characterized, the rat model has received less attention. Aim: To evaluate the effect of a single intratracheal elastase dose on lung pathological changes of Sprague-Dawley rats. Material and methods: Rats were injected with a single intratracheal elastase dose of 28 U/100 g body weight or saline and studied 7, 15, 30 and 365 days after injection. Results: Forty percent of rats died in the first 48 hours after injection, six were sacrificed at 7 days, 6 at 15 days, 7 at 30 days and 12 at 365 days. Progressive centroacinar emphysema was found from day 7 after elastase, with a persistent inflammatory reaction in the vicinity of emphysematous areas. Conclusions: Present findings differ from the panacinar emphysema described in the hamster using a similar elastase dose