TNF-alpha stimulates glucose uptake in L6 myoblasts.
Diabetes Res Clin Pract
; 32(1-2): 11-8, 1996 Apr.
Article
em En
| MEDLINE
| ID: mdl-8803477
ABSTRACT
The mechanism of TNF-alpha to regulate glucose metabolism remains unclear. To further delineate the TNF-alpha signal transduction pathway mediating glucose metabolism, we utilized L6 rat myoblasts which contain the receptors for the insulin-like growth factor-I (IGF-I) and TNF-alpha, and the ability of both ligands to stimulate glucose uptake was compared. IGF-I (6.5 nM) maximally stimulated glucose uptake 7-fold after 24 h incubation, while 23 nM TNF-alpha maximally stimulated glucose uptake 3-fold only after 48 h incubation. IGF-I receptor beta-subunit, insulin receptor substrate-1 (IRS-1), and mitogen-activated protein (MAP) kinase were all phosphorylated in response to 6.5 nM IGF-I after 10 min incubation. In contrast, the treatment with 23 nM TNF-alpha failed to phosphorylate either IGF-I receptor beta-subunit or IRS-1 but did phosphorylate MAP kinase as much as IGF-I did. Despite a similar extent to which TNF-alpha induced MAP kinase phosphorylation as IGF-I did, TNF-alpha stimulated glucose uptake less compared to IGF-I. The results indicate that MAP kinase phosphorylation is not sufficient for glucose uptake in L6 myoblasts. TNF-alpha-elicited signal transduction to glucose uptake may utilize a different pathway from that seen with IGF-I.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fator de Crescimento Insulin-Like I
/
Fator de Necrose Tumoral alfa
/
Receptor IGF Tipo 1
/
Receptores do Fator de Necrose Tumoral
/
Desoxiglucose
/
Glucose
Limite:
Animals
Idioma:
En
Revista:
Diabetes Res Clin Pract
Assunto da revista:
ENDOCRINOLOGIA
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Japão