Journal
AMERICAN JOURNAL OF PHYSIOLOGY-RENAL PHYSIOLOGY
Volume 295, Issue 6, Pages F1715-F1724Publisher
AMER PHYSIOLOGICAL SOC
DOI: 10.1152/ajprenal.90311.2008
Keywords
collecting duct; arginine vasopressin; aquaporin; urea transporters; extracellular nucleotides
Categories
Funding
- NIDDK NIH HHS [R01 DK041707, DK-41707, DK-62081, R01 DK062081-05, R01 DK062081] Funding Source: Medline
- NATIONAL INSTITUTE OF DIABETES AND DIGESTIVE AND KIDNEY DISEASES [R01DK062081, R01DK041707, R29DK041707] Funding Source: NIH RePORTER
Ask authors/readers for more resources
Osmotic reabsorption of water through aquaporin-2 (AQP2) in the inner medulla is largely dependent on the urea concentration gradients generated by urea transporter (UT) isoforms. Vasopressin (AVP) increases expression of both AQP2 and UT-A isoforms. Activation of the P2Y2 receptor (P2Y2-R) in the medullary collecting duct inhibits AVP-induced water flow. To gain further insights into the overarching effect of purinergic signaling on urinary concentration, we compared the protein abundances of AQP2 and UT-A isoforms between P2Y2-R knockout (KO) and wild-type (WT) mice under basal conditions and following AVP administration. Under basal conditions (a gel diet for 10 days), KO mice concentrated urine to a significantly higher degree, with 1.8-, 1.66-, and 1.29-fold higher protein abundances of AQP2, UT-A1, and UT-A2, respectively, compared with WT, despite comparable circulating AVP levels in both groups. Infusion of 1-desamino-8-D-arginine vasopressin (dDAVP; desmopressin; 1 ng/h sc) for 5 days resulted in 2.14-, 2.6-, and 2.22-fold higher protein abundances of AQP2, AQP3, and UT-A1, respectively, in the inner medullas of KO mice compared with WT mice. In response to acute (45 min) stimulation by AVP (0.2 unit/mouse sc), UT-A1 protein increased by 1.39- and 1.54-fold in WT and KO mice, respectively. These data suggest that genetic deletion of P2Y2-R results in increased abundances of key proteins involved in urinary concentration in the inner medulla, both under basal conditions and following AVP administration. Thus purinergic regulation may play a potential overarching role in balancing the effect of AVP on the urinary concentration mechanism.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available