[Role of sympathoadrenal activations in congestive heart failure].
Although sympathoneuronal activation plays a major role in maintaining circulatory homeostasis in decompensated heart failure, protracted activation adversely affects survival in patients with chronic heart failure. Endstage heart failure is associated with beta-adrenergic receptor subsensitivity phenomenon including downregulation of beta1-adrenergic receptors, uncoupling induced by receptor kinase activations, increased level of inhibitory guanine nucleotide binding protein. Abnormal calcium handling occurs as a result of dissociation of ryanodine receptors and its modulatory protein, FK506 binding proteins in addition to defective calcium uptake. Phosphoinositide 3-kinase gamma as well as defective neuronal uptake mechanism of norepinephrine have a pivotal role in mediating these alterations in adrenergic receptor signalings. In this regards, modulation of excessive adrenergic activations is essential to achieve successful management of patients with congestive heart failure.
Yoshikawa
Tsutomu
T
Cardiology Division, Department of Medicine, Keio University School of Medicine.