Fig. 3.

Effects of ouabain on signaling in cultured cardiomyocytes from WT and cav-1 KO mice. A: phosphoinositide-3 kinase (PI3K)α activity. Myocytes were incubated with or without 50 μM ouabain for 5 min. Cell lysates were immunoprecipitated (IP) with PI3K p85 subunit and assayed for PI3Kα activity as described in materials and methods (n = 4). *P < 0.05 vs. control (CON). B: Akt activation. Myocytes were incubated with 10, 50 μM ouabain for the indicated time (n = 4). Cell lysates were subjected to Western blots. Akt activation was assessed by the ratio of phosphorylated (p)-Akt/total Akt. C: ERK activation. Myocytes were incubated with 10, 50 μM ouabain or 100 nM ANG II for indicated time (n = 4). Cell lysates were subjected to Western blots. ERK activation was assessed by the ratio of p-ERK/ total ERK (n = 4). *P < 0.05 vs. 0 min. oua, Ouabain.