Effect of HS on phosphatidylinositol 3-kinase (PI3K) content in the membrane fraction of NRVM. A representative immunoblot is shown (bottom). Compared with control myocytes, myocytes subjected to HS contained significantly more PI3K in the membrane fraction (*P < 0.05, C vs. HS, n = 4; **P < 0.05, C+10'CI vs. HS+10'CI, n = 4). y-Axis data are plotted as fraction of control myocyte levels. β-Dystroglycan (a membrane protein) blotting confirmed equal loading between the samples.