cGMP signals modulate cAMP levels in a compartment-specific manner to regulate catecholamine-dependent signaling in cardiac myocytes.

Rationale: cAMP and cGMP are intracellular second messengers involved in heart pathophysiology. cGMP can potentially affect cAMP signals via cGMP-regulated phosphodiesterases (PDEs).

Objective: To study the effect of cGMP signals on the local cAMP response to catecholamines in specific subcellular compartments.

Dysregulation of cadherins in the intercalated disc of the spontaneously hypertensive stroke-prone rat.

The structural integrity of cardiac cells is maintained by the Ca(2+)-dependent homophilic cell-cell adhesion of cadherins. N-cadherin is responsible for this adhesion under normal physiological conditions. The role of cadherins in adverse cardiac pathology is less clear.

Onset of experimental severe cardiac fibrosis is mediated by overexpression of Angiotensin-converting enzyme 2.

Angiotensin-converting enzyme (ACE) 2 is a recently identified homologue of ACE. There is great interest in the therapeutic benefit for ACE2 overexpression in the heart. However, the role of ACE2 in the regulation of cardiac structure and function, as well as maintenance of systemic blood pressure, remains poorly understood.

Calcium/calmodulin-dependent protein kinase IIdelta associates with the ryanodine receptor complex and regulates channel function in rabbit heart.

Cardiac ryanodine receptors (RyR2s) play a critical role in excitation-contraction coupling by providing a pathway for the release of Ca(2+) from the sarcoplasmic reticulum into the cytosol. RyR2s exist as macromolecular complexes that are regulated via binding of Ca(2+) and protein phosphorylation/dephosphorylation. The present study examined the association of endogenous CaMKII (calcium/calmodulin-dependent protein kinase II) with the RyR2 complex and whether this enzyme could modulate RyR2 function in isolated rabbit ventricular myocardium.