Rethinking Cardiac Hypertrophy
In 1983, we reported that catecholamine activation of alpha-1-adrenergic receptors stimulated hypertrophy of cultured neonatal rat ventricular myocytes. This finding required reexamining the paradigm that myocardial hypertrophy was caused entirely by hemodynamic load and mechanical stimulation of cardiac myocytes. Research in many labs over the ensuing decades has identified multiple ligand-receptor-signalling systems which regulate cardiac hypertrophys. A paradigm has emerged that Gq-coupled receptors and the "fetal" gene program are causal in pathological or maladaptive hypertrophy, and research is directed to inhibiting this signaling. Surprisingly, alpha-1-adrenergic receptors, which are prototypical Gq-coupled receptors activating the fetal gene program, appear to be necessary and sufficient for an adaptive form of hypertrophy. This lecture will ask whether we need to keep rethinking cardiac hypertrophy.
- © 2010 by American Heart Association, Inc.