These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Efferent arterioles exclusively express the subtype 1A angiotensin receptor: functional insights from genetic mouse models.
    Author: Harrison-Bernard LM, Monjure CJ, Bivona BJ.
    Journal: Am J Physiol Renal Physiol; 2006 May; 290(5):F1177-86. PubMed ID: 16332932.
    Abstract:
    Angiotensin (ANG) type 1A (AT(1A)) receptor-null (AT(1A)(-/-)) mice exhibit reduced afferent arteriolar (AA) constrictor responses to ANG II compared with wild-type (WT) mice, whereas efferent arteriolar (EA) responses are absent (Harrison-Bernard LM, Cook AK, Oliverio MI, and Coffman TM. Am J Physiol Renal Physiol 284: F538-F545, 2003). In the present study, the renal arteriolar constrictor responses to norepinephrine (NE) and/or ANG II were determined in blood-perfused juxtamedullary nephrons from kidneys of AT(1A)(-/-), AT(1B) receptor-null (AT(1B)(-/-)), and WT mice. Baseline AA diameter in AT(1A)(-/-) mice was not different from that in WT mice (13.1 +/- 0.9 and 12.6 +/- 0.9 microm, n = 7 and 8, respectively); however, EA diameters were significantly larger (17.3 +/- 1.4 vs. 11.7 +/- 0.4 microm, n = 10 and 8) in AT(1A)(-/-) than in WT mice. Constriction of AA (-40 +/- 8 and -51 +/- 6% at 1 microM NE) and EA (-29 +/- 6 and -38 +/- 3% at 1 microM NE) in response to 0.1-1 microM NE was similar in AT(1A)(-/-) and WT mice. Baseline diameters of AA (13.5 +/- 0.7 and 14.2 +/- 0.9 microm, n = 9 and 10) and EA (15.4 +/- 1.0 and 15.0 +/- 0.7 microm, n = 11 and 9) and ANG II (0.1-10 nM) constrictor responses of AA (-25 +/- 4 and -31 +/- 5% at 10 nM) and EA (-32 +/- 6 and -35 +/- 7% at 10 nM) were similar in AT(1B)(-/-) and WT mice, respectively. ANG II-induced constrictions were eliminated by AT(1) receptor blockade with 4 microM candesartan. Taken together, our data demonstrate that AA and EA responses to NE are unaltered in the absence of AT(1A) receptors, and ANG II responses remain intact in the absence of AT(1B) receptors. Therefore, we conclude that AT(1A) and AT(1B) receptors are functionally expressed on the AA, whereas the EA exclusively expresses the AT(1A) receptor.
    [Abstract] [Full Text] [Related] [New Search]