Examinando por Autor "Arribas, Carmen"

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Changes in the neuroendocrine control of energy homeostasis by adiposity signals during aging
(Experimental Gerontology, 2009) Carrascosa, Jose María; Ros, Manuel; Fernández-Agulló, Teresa; Arribas, Carmen
Development of Insulin Resistance During Aging: Involvement of Central Processes and Role of Adipokines
(Current Protein and Peptide Science, 2011-06-01) Carrascosa, Jose M.; Andres, Antonio; Ros, Manuel; Bogonez, Elena; Arribas, Carmen; Fernandez-Agullo, Teresa; DeSolis, Alain J.; Gallardo, Nilda; Martinez, Carmen
Aging in mammals associates with the development of peripheral insulin resistance. Additionally, adiposity usually increases with aging and this could play a relevant role in the gradual impairment of insulin action. In fact, fat accretion leads to changes in the expression and circulating concentrations of factors originated in adipose tissue like leptin, resistin and inflammatory cytokines which have been shown to modulate insulin signaling in insulin target tissues acting both, directly or through the central nervous system. Even insulin action on peripheral target tissues has been recently demonstrated to be partially mediated by its central action, suggesting that a decrease in central insulin action could be involved in the development of peripheral insulin resistance. In the present review we analyze the available research data on aging-associated insulin resistance making emphasis in the following aspects: 1) The time-course of development of overall insulin resistance and the evolution of changes in circulating adipokines; 2) The effect of caloric restriction and the decrease of adiposity in insulin action; 3) The influence of changes in the central action of factors like leptin or insulin in the development and maintenance of insulin resistance during aging.
Epoxy Composites Reinforced with ZnO fromWaste Alkaline Batteries
(MDPI, 2022-04-13) Lorero, Isaac; Campo, Mónica; Arribas, Carmen; González Prolongo, Margarita; Antonio López, Félix; González Prolongo, Silvia
La pila alcalina de zinc es una de las fuentes más populares de energía eléctrica portátil, con un consumo de más de 300.000 toneladas al año. Por ello, es fundamental reciclar sus componentes. En este trabajo, proponemos el uso de micropartículas de óxido de zinc (ZnO) recuperadas de pilas gastadas como cargas de resinas epoxi. Estos nanocompuestos pueden emplearse como recubrimientos o pigmentos protectores y como compuestos estructurales de alta estabilidad térmica. La adición de nanorrellenos cerámicos puede mejorar las propiedades térmicas y mecánicas, así como la dureza y la hidrofobicidad, de las resinas epoxi, dependiendo de varios factores. En consecuencia, se han fabricado diferentes nanocomposites reforzados con ZnO reciclado y nanopartículas comerciales de ZnO y TiO2 con distintos contenidos de nanorelleno. La adición de cargas cerámicas produce un pequeño aumento de la temperatura de transición vítrea (<2%), junto con una potenciación del efecto barrera de la resina epoxi, reduciendo el coeficiente de difusión de agua (<21%), aunque la absorción máxima de agua permanece constante. La absorción de agua del nanocomposite es totalmente reversible mediante un tratamiento térmico posterior, recuperando su comportamiento termomecánico inicial. El ángulo de contacto con el agua (WCA) también aumenta (~12%) con la presencia de partículas cerámicas, aunque la mayor hidrofobicidad (35%) se obtiene cuando la resina epoxi reforzada con micropartículas de ZnO recicladas se trata con ácido esteárico y ácido acético, induciendo el incremento de la rugosidad superficial.
Impaired Central Insulin Response in Aged Wistar Rats: Role of Adiposity
(Endocrinology, 2007-11-01) García-San Frutos, Miriam; Fernandez-Agullo, Teresa; De Solis, Alain J.; Andres, Antonio; Arribas, Carmen; Carrascosa, Jose M.; Ros, Manuel
Insulin, like leptin, is considered as a lipostatic signal acting at a central level. Aging and age-associated adiposity have been related to the development of leptin resistance in Wistar rats. In the present article, hypothalamic insulin response during aging has been studied in Wistar rats. Thus, the effects of intracerebroventricular infusion of insulin during a week on food intake and body weight as well as insulin signal transduction after acute intracerebroventricular insulin administration have been studied in 3-, 8-, and 24-month-old rats. To explore the possible role of age-associated adiposity, these experiments were also performed in 8- and 24-month-old rats after 3 months of food restriction to reduce visceral adiposity index to values below those of young animals. Intracerebroventricular administration of insulin during a week was more efficient at reducing food intake and body weight in 3-month-old rats than in 8- and 24-month-old rats. Hypothalamic insulin-stimulated insulin receptor, GSK3, AKT, and p70S6K phosphorylation decreased with aging. Insulin receptor and IRS-2 phosphoserine was increased in 24-month-old rats. Food restriction improved both insulin responsiveness and insulin signaling. These data suggest that Wistar rats develop hypothalamic insulin resistance with aging. This can be explained by alterations of the signal transduction pathway. The fact that food restriction improves central insulin response and signal transduction points to the age-associated adiposity as a key player in the development of central insulin resistance.
The expression of rat resistin isoforms is differentially regulated in visceral adipose tissues: effects of aging and food restriction
(Metabolism Clinical and Experimental, 2009) M. Fernández, Carmen; Moltó, Eduardo; Gallardo, Nilda; Arco, Araceli del; Martíniz, Carmen; Andrés, Antonio; Ros, Manuel; Carrascosa, Jose María; Arribas, Carmen