Fig 3. Testosterone inhibits GSK-3β in cardiac myocytes.

Cardiac myocytes were stimulated with 100 nM testosterone for 15, 30, 60, 90, and 120 min and subjected to Western blot analysis to determine (A) GSK-3β phosphorylation (p-GSK-3β, Ser9) and protein levels (n = 5) and (B) β-catenin phosphorylation and total β-catenin protein levels (n = 4). The densitometric analyses show the ratio of phosphorylated versus total protein. Testosterone increased GSK-3β phosphorylation at Ser9 and decreased β-catenin phosphorylation at Ser33, Ser37, and Thr41 after 30 min of stimulation. (C) Cardiac myocytes were stimulated with 100 nM testosterone for 3, 6, 9, 12, and 24 h and total β-catenin protein accumulation was determined through Western blotting (n = 5). Values are presented as the mean ± SEM. *p < 0.05, **p < 0.01, and ***p < 0.001 vs. control non-stimulated condition.