RESUMEN

Growth hormone (GH) excess causes an increment in the metabolic rate and in reactive oxygen species generation, which accelerate the ageing process in mammals. Considering that there is no information on this subject in fish, the aim of the present study was to evaluate the excess GH effect on senescence in a zebrafish (Danio rerio) transgenic model. In order to reach this objective, we analyzed the phenotype of spinal curvature and expression of genes related to the anti-oxidant defense system and myogenesis in muscle of 8 and 30 months old GH-transgenic males. Gene expression analyses revealed that both superoxide dismutase isoforms were down-regulated only in 30 months old animals, while glutamate cysteine ligase was down-regulated in GH-transgenic zebrafish. Acceleration of the spinal curvature and a reduction in the expression of miogenin at both ages and MyoD in the old fish were also observed. Although neurolipofuscin accumulation was not significant in GH-transgenic zebrafish, the estimation of maximum longevity based on the von Bertalanffy growth function was significantly lower in this group. The results obtained here indicate that GH overexpression reduces the transcription of anti-oxidant defense system and myogenesis-related genes, which probably accelerates senescence in the zebrafish transgenic model used.

Asunto(s)

Glutamato-Cisteína Ligasa/genética , Hormona del Crecimiento/metabolismo , Desarrollo de Músculos/genética , Curvaturas de la Columna Vertebral/metabolismo , Superóxido Dismutasa/genética , Pez Cebra/metabolismo , Envejecimiento/fisiología , Animales , Animales Modificados Genéticamente/genética , Animales Modificados Genéticamente/metabolismo , Antioxidantes/metabolismo , Carpas/genética , Amplificación de Genes , Regulación del Desarrollo de la Expresión Génica , Glutatión/genética , Glutatión/metabolismo , Gráficos de Crecimiento , Hormona del Crecimiento/genética , Hormona del Crecimiento/fisiología , Peroxidación de Lípido/genética , Lipofuscina , Masculino , Músculo Esquelético/metabolismo , Fenotipo , Reacción en Cadena de la Polimerasa , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , ARN Mensajero/metabolismo , Radiografía , Curvaturas de la Columna Vertebral/diagnóstico por imagen , Pez Cebra/genética