obsolete ANPR-A:ANP complex true ame cellular_component An example of this is [ANPR-A:ANP] in [rat] (P18910:P01161-PRO_0000391785) in PMID:15117952 (inferred from direct assay). GO:1990618 2015-01-23T15:17:47Z OBSOLETE. The ANPR-A:ANP complex is composed of the hormone AMP bound to the extracellular domain of ANPR-A domain. It is formed in the atrium in response to atrial distension (high blood volume) and leads to guanylate cyclase activity of the ANPR-A receptor, 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. Therefore, ANPR-A:ANP complex plays a major role in the regulation of blood pressure and salt-fluid volume homeostasis. ANPR-A:ANP complex