Insulin signaling proteins in pancreatic islets of insulin-resistant rats induced by glucocorticoid
Biol. Res
;
44(3): 251-257, 2011. ilus
Artículo
en Inglés
| LILACS
| ID: lil-608621
ABSTRACT
Chronic administration of glucocorticoids induces insulin resistance that is compensated by an increase in p-cell function and mass. Since insulin signaling is involved in the control of p-cell function and mass, we investigated the content of insulin pathway proteins in pancreatic islets. Rats were made insulin resistant by daily administration of dexamethasone (1mg/kg, b.w., i.p.) for 5 consecutive days (DEX), whilst control rats received saline (CTL). Circulating insulin and insulin released from isolated islets were measured by radioimmunoassay whereas the content of proteins was analyzed by Western blotting. DEX rats were hyperinsulinemic and exhibited augmented insulin secretion in response to glucose (P < 0.01). The IRa-subunit, IRS-1, Shc, AKT, p-p70S6K, ERK1/2, p-ERK1/2, and glucocorticoid receptor protein levels were similar between DEX and CTL islets. However, the IRp-subunit, p-IRp-subunit, IRS-2, PI3-K, p-AKT and p70S6K protein contents were increased in DEX islets (P < 0.05). We conclude that IRS-2 may have a major role, among the immediate substrates of the insulin receptor, to link activated receptors to downstream signaling components related to islet function and growth in this insulin-resistant rat model.
Texto completo:
Disponible
Índice:
LILACS (Américas)
Asunto principal:
Resistencia a la Insulina
/
Dexametasona
/
Islotes Pancreáticos
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Proteínas Sustrato del Receptor de Insulina
/
Glucocorticoides
/
Insulina
Límite:
Animales
Idioma:
Inglés
Revista:
Biol. Res
Asunto de la revista:
Biologia
Año:
2011
Tipo del documento:
Artículo
País de afiliación:
Brasil
Institución/País de afiliación:
Universidade Estadual Paulista -UNESP/BR
/
Universidade Estadual de Campinas - UNICAMP/BR
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