Blocking a receptor-regulating protein present in the adrenals prevents a failing heart from going into overdrive and allows it to relax and heal, according to a report in Nature Medicine by researchers at the Center for Translational Medicine at Thomas Jefferson University in Philadelphia.

The protein, called G protein-coupled receptor kinase 2 (GRK2), is responsible for the desensitization of adrenaline receptors in the heart and is essential for proper heart development. However, in heart failure, enhanced myocardial GRK2 activity is known to shut off and desensitize adrenergic receptor beta. The Thomas Jefferson researchers now have discovered there are also high levels of GRK2 in the chromaffin cells in the adrenal gland, which cause down-regulation and desensitization of adrenergic receptor alpha 2.