Renal segmental microvascular responses to ANG II in AT1A receptor null mice.

Journal Article (Journal Article)

The relative contributions of AT(1A) and AT(1B) receptors to afferent arteriolar autoregulatory capability and afferent and efferent arteriolar responses to ANG II are not known. Experiments were conducted in kidneys from wild-type (WT) and AT(1A)-/- mice utilizing the in vitro blood-perfused juxtamedullary nephron technique. Direct measurements of afferent (AAD) and efferent arteriolar diameters (EAD) were assessed at a renal arterial pressure of 100 mmHg. AAD averaged 14.8 +/- 0.8 microm for WT and 14.9 +/- 0.8 microm for AT(1A)-/- mice. AAD significantly decreased by 7 +/- 1, 16 +/- 1, and 26 +/- 2% for WT mice and by 11 +/- 1, 20 +/- 2, and 30 +/- 3% for AT(1A)-/- mice (120, 140, 160 mmHg). AAD autoregulatory capability was not affected by the absence of AT(1A) receptors. AAD responses to 10 nM ANG II were significantly blunted for AT(1A)-/- mice compared with WT (-22 +/- 2 vs. -37 +/- 5%). ANG II (0.1-10 nM) failed to elicit any change in EAD for AT(1A)-/- mice. AAD and EAD reductions in ANG II were blocked by 1 microM candesartan. We conclude that afferent arteriole vasoconstrictor responses to ANG II are mediated by AT(1A) and AT(1B) receptors, whereas efferent arteriolar vasoconstrictor responses to ANG II are mediated by only AT(1A) receptors in the mouse kidney.

Full Text

Duke Authors

Cited Authors

  • Harrison-Bernard, LM; Cook, AK; Oliverio, MI; Coffman, TM

Published Date

  • March 2003

Published In

Volume / Issue

  • 284 / 3

Start / End Page

  • F538 - F545

PubMed ID

  • 12429556

International Standard Serial Number (ISSN)

  • 1931-857X

Digital Object Identifier (DOI)

  • 10.1152/ajprenal.00340.2002


  • eng

Conference Location

  • United States