Abstract: FR-OR133

Renal Phenotype of P2Y12 Receptor Knockout Mice

Session Information

Category: Fluid, Electrolytes, and Acid-Base

  • 702 Water/Urea/Vasopressin, Organic Solutes

Authors

  • Kishore, Bellamkonda K., Univ. of Utah and VA Medical Center, Salt Lake City, Utah, United States
  • Hansson, Kenny M., AstraZeneca, Cardiovascular and Metabolic Diseases iMED, Mölndal, Sweden
  • Liu, Tao, Univ. of Utah & VA Med Ctr, Salt Lake City, Utah, United States
  • Magnell, Kerstin, AstraZenecaR&D, Mölndal, Sweden
  • Carlson, Noel G., VA Salt Lake City Health Care System, Salt Lake City, Utah, United States
  • Zhang, Yue, Univ. of Utah & VA Medical Center, Salt Lake City, Utah, United States
Background

Previously we reported that pharmacological blockade of P2Y12 receptor (R) potentiates the action of arginine vasopressin (AVP) on renal medullary collecting duct (mCD). To establish that the observed effect is mediated through P2Y12-R, we evaluated the renal phenotype of P2Y12-R global knockout (KO) mice.

Methods

The P2ry12 gene was disrupted by targeted homologous recombination in ES cells. Urinary excretion of AVP, cAMP, PGE2, Na and K was assayed in adult homozygous KO and syngeneic C57/Bl6 wild type (WT) mice under basal conditions. Primary cultures of mCD cells from KO and WT mice were stimulated with 0.1 nM of dDAVP for 24 h, and assayed for cAMP generation, and mRNA expression of AQP2.

Results

The urine from KO mice showed significant increases in cAMP, PGE2 and K compared to WT mice (see Table). Comparisons between mCD cells derived from KO and WT mice showed significantly higher production of cAMP in response to stimulation with dDAVP (16-fold vs. 4-fold, P < 0.006, N = 6). Significantly higher level of mRNA expression of AQP2 was observed in mCD from KO vs. WT mice after dDAVP stimulation (2.43-fold, P < 0.04).

Conclusion

These findings are consistent with our previous observations and show that loss of P2Y12-R by either pharmacological blockade or genetic deletion potentiates the action of AVP/dDAVP on mCD. These data also reveal that P2Y12-R may play a role in renal handling of sodium and potassium.

UrineWTP2Y12 KOP Value
AVP*432 ± 55 (5)518 ± 67 (5)= 0.175
cAMP**23 ± 2 (6)35 ± 6 (6)< 0.050
PGE2↑377 ± 25 (5)566 ± 98 (5)< 0.050
Sodium#131 ± 13 (4)184 ± 17 (6)= 0.057
Postassium#289 ± 34 (4)426 ± 45 (6)< 0.040

Values are mean ± se (N): Statistical analysis by ANOVA *pmoles/24 h/20 g body weight; **nmoles/24 h/20 g body weight; ↑pg/24 h/20 g body weight; #µmol/24 h/20 g body weight;

Funding

  • Veterans Affairs Support