摘要

AVR/NAVR deficiency lowers blood pressure and differentially affects urinary concentrating ability, cognition, and anxiety-like behavior in male and female mice. Physiol Genomics 43: 32-42, 2011. First published October 5, 2010; doi:10.1152/physiolgenomics.00154.2010.-Arginine vasopressin (AVP) and angiotensin II (ANG II) are distinct peptide hormones involved in multiple organs modulating renal, cardiovascular, and brain functions. They achieve these functions via specific G protein-coupled receptors, respectively. The AVR/NAVR locus encodes two overlapping V2-type vasopressin isoreceptors: angiotensin-vasopressin receptor (AVR) responding to ANG II and AVP equivalently, and nonangiotensin vasopressin receptor (NAVR), which binds vasopressin exclusively. AVR and NAVR are expressed from a single gene by alternative promoter usage that is synergistically upregulated by testosterone and estrogen. This study tested the hypothesis that AVR/NAVR modulates urinary concentrating ability, blood pressure, and cognitive performance in vivo in a sex-specific manner. We developed a C57BL/6 inbred AVR/NAVR(-/-) knockout mouse that showed lower blood pressure in both male and female subjects and a urinary-concentrating defect restricted to male mice. We also detected sex-specific effects on cognitive and anxiety-like behaviors. AVR/NAVR(-/-) male mice exhibited impaired visuospatial and associative learning, while female mice showed improved performance in both type of cognition. AVR/NAVR deficiency produced an anxiolytic-like effect in female mice, while males were unaffected. Analysis of AVR- and NAVR-mediated phosphorylation/dephosphorylation of signaling proteins revealed activation/deactivation of known modulators of cognitive function. Our studies identify AVR/NAVR as key receptors involved in blood pressure regulation and sex-specific modulation of renal water homeostasis, cognitive function, and anxiety-like behavior. As such, the AVR/NAVR receptor system provides a molecular mechanism for sexually diergic traits and a putative common pathway for the emerging association of hypertension and cognitive decline and dementia.