Molero J C, Martínez C, Andrés A, Satrústegui J, Carrascosa J M
Departamento de Biología Molecular, Centro de Biología Molecular (CSIC), Facultad de Ciencias, Universidad Autónoma, Cantoblanco, Madrid, Spain.
FEBS Lett. 1998 Mar 27;425(2):298-304. doi: 10.1016/s0014-5793(98)00258-0.
Vanadate stimulates adipocyte 2-deoxyglucose transport and GLUT-4 translocation to the membrane through an insulin receptor-independent but wortmannin-inhibitable pathway. Vanadate stimulates PI 3-kinase in anti-IRS-1 immunoprecipitates and the binding between IRS-1 and the p85alpha subunit of PI 3-kinase. In insulin-resistant adipocytes from old rats vanadate fully stimulates IRS-1-associated PI 3-kinase, but partially activates glucose uptake. We conclude that: (a) vanadate stimulates 2-deoxyglucose uptake using a pathway that converges with that of insulin at the level of PI 3-kinase; and (b) adipocytes from old rats are defective in the insulin pathway at steps located both upstream and downstream of PI 3-kinase.
