Scanning densitometry analysis of the effect of metformin on IGF-I-stimulated IGF-IR, AKT and ERK1/2 phosphorylation.

Optical density was expressed as pIGF-IR, pAKT and pERK values normalized to the corresponding total proteins. A value of 100% was given to the optical density of IGF-I treated cells. The table shows the result of a typical experiment, repeated three times with similar results.−, untreated cells; I, IGF-I-treated cells; M, metformin-treated cells; M+I, metformin and IGF-I-treated cells.