Nephron-specific deletion of the prorenin receptor in mice caused a urine concentration defect with significantly lower urine osmolality, higher water intake, and higher urine volume.
Does nephron-specific deletion of the prorenin receptor alter renal water excretion in mice?
Nephron-specific deletion of the prorenin receptor in adult mice causes a urine concentration defect, suggesting that the PRR modulates renal water excretion via AVP responsiveness.
p-value: p=<0.05
The prorenin receptor (PRR), a recently discovered component of the renin-angiotensin system, is expressed in the nephron in general and the collecting duct in particular. However, the physiological significance of nephron PRR remains unclear, partly due to developmental abnormalities associated with global or renal-specific PRR gene knockout (KO). Therefore, we developed mice with inducible nephron-wide PRR deletion using Pax8-reverse tetracycline transactivator and LC-1 transgenes and loxP flanked PRR alleles such that ablation of PRR occurs in adulthood, after induction with doxycycline. Nephron-specific PRR KO mice have normal survival to ∼1 yr of age and no renal histological defects. Compared with control mice, PRR KO mice had 65% lower medullary PRR mRNA and protein levels and markedly diminished renal PRR immunofluorescence. During both normal water intake and mild water restriction, PRR KO mice had significantly lower urine osmolality, higher water intake, and higher urine volume compared with control mice. No differences were seen in urine vasopressin excretion, urine Na(+) and K(+) excretion, plasma Na(+), or plasma osmolality between the two groups. However, PRR KO mice had reduced medullary aquaporin-2 levels and arginine vasopressin-stimulated cAMP accumulation in the isolated renal medulla compared with control mice. Taken together, these results suggest nephron PRR can potentially modulate renal water excretion.
Ramkumar et al. (Thu,) conducted a other in Urine concentration defect. Nephron-specific prorenin receptor (PRR) deletion vs. Control mice was evaluated on Urine osmolality, water intake, and urine volume (p=<0.05). Nephron-specific deletion of the prorenin receptor in mice caused a urine concentration defect with significantly lower urine osmolality, higher water intake, and higher urine volume.