Apelin Counteracts Vasopressin-Induced Water Reabsorption via Cross Talk Between Apelin and Vasopressin Receptor Signaling Pathways in the Rat Collecting Duct

• DOI: 10.1210/en.2014-1257
• Publication Date: 2014-08-26T17:20:01Z
• Authors: Annette Hus-Citharel; Laurence Bodineau; Alain Frugière; Fanny Joubert; Nadine Bouby; Catherine Llorens...
• Keywords: Apelin

Apelin receptors (ApelinRs) are expressed along an increasing cortico-medullary gradient in collecting ducts (CDs). We showed here that iv injection of apelin 17 (K17F) lactating rats characterized by increases both synthesis and release arginine vasopressin (AVP) increased diuresis concomitantly with a significant decrease urine osmolality no change Na(+) K(+) excretion. Under these conditions, we also observed apical aquaporin-2 immunolabeling CD, gradient, suggesting K17F-induced could be linked to direct action on CD. then examined the potential cross talk between V1a AVP receptor (V1a-R), V2 (V2-R) ApelinR signaling pathways outer medullary CD (OMCD) inner microdissected rat In OMCD, expressing 3 receptors, K17F inhibited cAMP production Ca(2+) influx induced 1-desamino-8-D-arginine V2-R agonist. Similar effects were only ApelinR. contrast, 51% stimulation V1a-R presence antagonist SR121463B, possibly enhancing physiological effect V2-R. Thus, diuretic is not due central inhibiting blood circulation as previously shown but counteracting antidiuretic occurring via