In situ phosphorylation of Akt and ERK1/2 in rat mammary gland, colon, and liver following treatment with human insulin and IGF-1.
Toxicol Pathol
; 39(4): 623-40, 2011 Jun.
Article
en En
| MEDLINE
| ID: mdl-21558470
ABSTRACT
High doses of insulin and the insulin analog AspB10 have been reported to increase mammary tumor incidence in female rats likely via receptor-mediated mechanisms, possibly involving enhanced IGF-1 receptor activation. However, insulin and IGF-1 receptor functionality and intracellular signaling in the rat mammary gland in vivo is essentially unexplored. The authors investigated the effect of a single subcutaneous dose of 600 nmol/kg human insulin or IGF-1 on Akt and ERK1/2 phosphorylation in rat liver, colon, and mammary gland. Rat tissues were examined by Western blotting and immunohistochemistry by phosphorylation-specific antibodies. Insulin as well as IGF-1 caused Akt phosphorylation in mammary epithelial cells, with myoepithelial and basal epithelial cells being most sensitive. IGF-1 caused stronger Akt phosphorylation than insulin in mammary gland epithelial cells. Phosphorylation of ERK1/2 was not influenced by insulin or IGF-1. Rather, in liver and mammary gland P-ERK1/2 appeared to correlate with estrous cycling, supporting that ERK1/2 has important physiological roles in these two organs. In short, these findings supported that the rat mammary gland epithelium expresses functional insulin and IGF-1 receptors and that phosphorylation of Akt as well as ERK1/2 may be of value in understanding the effects of exogenous insulin in the rat mammary gland and colon.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Factor I del Crecimiento Similar a la Insulina
/
Proteína Quinasa 1 Activada por Mitógenos
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Proteína Quinasa 3 Activada por Mitógenos
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Proteínas Proto-Oncogénicas c-akt
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Insulina
Límite:
Animals
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Female
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Humans
Idioma:
En
Revista:
Toxicol Pathol
Año:
2011
Tipo del documento:
Article
País de afiliación:
Dinamarca