|
|
||||||||
Department of 1Physiology and 3Hypertension and Renal Center of Excellence, Tulane University Health Sciences Center School of Medicine, New Orleans, Louisiana 70112; and Department of 2Pathology, University of North Carolina, Chapel Hill, North Carolina 27599
Submitted 5 March 2003 ; accepted in final form 18 June 2003
The deficiency of Npr1 [genetic determinant of natriuretic peptide receptor A (NPRA)] increases arterial pressures and causes hypertensive heart disease in mice similar to those seen in untreated human hypertensive patients. However, the quantitative role of NPRA in mediating the renal responses to blood volume expansion remains uncertain. To determine the specific contribution of NPRA in mediating the signaling mechanisms responsible for natriuretic and diuretic responses to nondilutional intravascular expansion, we administered whole blood to anesthetized Npr1 homozygous null mutant (0-copy), wild-type (2-copy), and gene-duplicated (4-copy) mice. In wild-type (2-copy) animals, urinary flow (µl · min1 · g kidney wt1) increased from 4.9 ± 1.0 to 14.4 ± 1.8 and sodium excretion (µeq · min1 · g kidney wt1) from 1.15 ± 0.22 to 3.11 ± 0.60, associated with a rise in glomerular filtration rate (GFR; ml · min1 · g kidney wt1) from 0.63 ± 0.03 to 0.82 ± 0.09 and renal plasma flow (RPF; ml · min1 · g kidney wt1) from 2.96 ± 0.17 to 4.36 ± 0.41, whereas arterial pressure did not significantly increase. After volume expansion, 0-copy mice showed significantly lesser increases in urinary flow (P < 0.001) and sodium excretory (P < 0.001) responses even though the increases in arterial pressures were greater (P < 0.001) compared with 2-copy mice. The 4-copy mice showed augmented responses in urinary flow (P < 0.01) and sodium excretion (P < 0.001) along with rises in both GFR (P < 0.01) and RPF (P < 0.01) compared with 2-copy wild-type mice. These results establish that NPRA activation is the predominant mechanism mediating the natriuretic, diuretic, and renal hemodynamic responses to acute blood volume expansion.
sodium excretion; cGMP; gene disruption; gene duplication
This article has been cited by other articles:
![]() |
P. Kumar and K. N. Pandey Cooperative Activation of Npr1 Gene Transcription and Expression by Interaction of Ets-1 and p300 Hypertension, July 1, 2009; 54(1): 172 - 178. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Zhao, D. M. Seth, and L. G. Navar Enhanced Distal Nephron Sodium Reabsorption in Chronic Angiotensin II-Infused Mice Hypertension, July 1, 2009; 54(1): 120 - 126. [Abstract] [Full Text] [PDF] |
||||
![]() |
T. Aoyagi, Y. Izumi, M. Hiroyama, T. Matsuzaki, Y. Yasuoka, A. Sanbe, H. Miyazaki, Y. Fujiwara, Y. Nakayama, Y. Kohda, et al. Vasopressin regulates the renin-angiotensin-aldosterone system via V1a receptors in macula densa cells Am J Physiol Renal Physiol, July 1, 2008; 295(1): F100 - F107. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Zhao and L. G. Navar Acute Angiotensin II Infusions Elicit Pressure Natriuresis in Mice and Reduce Distal Fractional Sodium Reabsorption Hypertension, July 1, 2008; 52(1): 137 - 142. [Abstract] [Full Text] [PDF] |
||||
![]() |
E. Vellaichamy, D. Zhao, N. Somanna, and K. N. Pandey Genetic disruption of guanylyl cyclase/natriuretic peptide receptor-A upregulates ACE and AT1 receptor gene expression and signaling: role in cardiac hypertrophy Physiol Genomics, October 19, 2007; 31(2): 193 - 202. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. Zhao, E. Vellaichamy, N. K. Somanna, and K. N. Pandey Guanylyl cyclase/natriuretic peptide receptor-A gene disruption causes increased adrenal angiotensin II and aldosterone levels Am J Physiol Renal Physiol, July 1, 2007; 293(1): F121 - F127. [Abstract] [Full Text] [PDF] |
||||
![]() |
D. G. Gardner, S. Chen, D. J. Glenn, and C. L. Grigsby Molecular Biology of the Natriuretic Peptide System: Implications for Physiology and Hypertension Hypertension, March 1, 2007; 49(3): 419 - 426. [Full Text] [PDF] |
||||
![]() |
L. J. Mullins, M. A. Bailey, and J. J. Mullins Hypertension, Kidney, and Transgenics: A Fresh Perspective Physiol Rev, April 1, 2006; 86(2): 709 - 746. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |