| Definition: |
A receptor complex composed of two ANPR-A molecules and expressed in the heart atrium in mammals; it plays a major role in the regulation of blood pressure and salt-fluid volume homeostasis. Binding of the ligand AMP in response to atrial distension (high blood volume) leads to guanylate cyclase activity of the ANPR-A receptor complex, thereby elevating intracellular cGMP levels. The end result is a reduction in blood volume and, therefore, a reduction in cardiac output and systemic blood pressure. |