Module 12: Figure physiological and pathological hypertrophy
Signalling pathways in physiological and pathophysiological cardiac hypertrophy.
In physiological hypertrophy, action potentials generate a Ca2+ signal that controls contraction and may also stabilize the normal cardiac signalsome by maintaining the adult genes. The insulin-like growth factor 1 (IGF-1) that is produced during exercise uses this adult template when it activates protein synthesis, acting through the PtdIns 3-kinase (PI 3-K) signalling pathway. During pathological hypertrophy, pressure overload activates signalling pathways that alter the nature of the Ca2+ signal (*), which activates a foetal set of genes that results in a remodelled cardiac signalsome that results in heart disease.