XXXX and @entity2690 -like growth factor-1 action on human skeletal muscle: preferential effects of @entity442 in type 2 @entity6 subjects.

@entity12561 @entity6 @entity442 @entity2690 @entity7964 @entity413 @entity29227
The metabolic actions of @entity29227 ( @entity442 ) were compared in cultured skeletal muscle cells from @entity7964 ( @entity7964 ) and type 2 @entity6 subjects. @entity2690 stimulated @entity413 uptake with comparable sensitivity in @entity7964 (EC(50) = 2.0 +/- 0.7 nmol/L) and @entity6 (1.3 +/- 0.4) cells. @entity442 sensitivity for uptake stimulation was similar in @entity7964 (EC(50) = 0.30 +/- 0.06 nmol/L) and type 2 cells (0.37 +/- 0.01). In @entity7964 cells, @entity2690 and @entity442 were equally potent for stimulation of @entity413 uptake and glycogen synthase (GS) activity. However, in @entity6 cells, maximal @entity2690 stimulation of both responses was only half of the increases due to @entity442 . Final absolute activities after @entity442 stimulation were still lower in @entity6 cells compared with cells from @entity7964 subjects. Hormonal stimulation of Akt phosphorylation exhibited the same behavior as metabolic responses; comparable for @entity2690 and @entity442 in @entity7964 muscle, while @entity442 was significantly more effective in @entity6 cells. Both @entity2690 receptor (IR) binding and receptor protein expression were similar in @entity7964 and @entity6 cells. @entity442 binding and receptor protein expression were not significantly different in @entity6 compared with @entity7964 cells. The expression of IGF-binding proteins (IGFBP) 3, 5, and 6 were similar in @entity7964 and @entity6 cells; @entity12561 was slightly, but significantly higher, in @entity6 cells. While @entity2690 and @entity442 are equally effective on metabolic responses in @entity7964 muscle, @entity6 muscle cells are markedly more resistant to @entity2690 than @entity442 . The greater metabolic activity of @entity442 in type 2 @entity6 muscle may provide new insights into the mechanisms of @entity2690 resistance in skeletal muscle.
