AKT1 and cardiac hypertrophy: In this work, the coincidence of an increase in p-Akt in the left ventricles with a time course similar to that reported in the left ventricles of hyperthyroid mice, in which the transient increase in Akt was also linked to cardiac hypertrophy and enhanced function (12), suggests by analogy a causal relationship between transient Akt activation and hypertrophy in the rat heart.