title: Angiotensin II type 1 autoantibody induced hypertension during pregnancy is associated with renal endothelial dysfunction.
abstract: BACKGROUND
  Previous investigations suggested that agonistic autoantibodies to the angiotensin II type I receptor (AT1-AA) might mediate a hypertensive response through dysregulation of the endothelin-1 system. AT1-AA induced hypertension was attenuated by the AT1 receptor and/or endothelin-1 type A receptor antagonists.
  
  
  OBJECTIVE
  This study was undertaken to determine if AT1-AA induced hypertension was associated with renal endothelial dysfunction.
  
  
  METHODS
  We compared the vascular reactivity of renal interlobar arteries from normal pregnant control rats and AT1-AA long-term infused pregnant rats in the presence and absence of endothelin type A (ET(A)) receptor antagonism. Renal endothelial function was tested using isolated renal interlobar arteries in a pressure myograph, which were exposed to acetylcholine or sodium nitroprusside.
  
  
  RESULTS
  Vasodilatory responses to the endothelial-dependent agonist acetylcholine were impaired in AT1-AA rats (74 [10]%) compared with normal pregnant controls (95 [5]%, P < 0.05). In the presence of ET(A) receptor antagonism, no differences were observed between controls or the AT1-AA treated group with regard to endothelial-dependent (acetylcholine) relaxation.
  
  
  CONCLUSIONS
  AT1-AA induced hypertension during pregnancy was associated with disparate renal endothelial responses to acetylcholine. The difference in renal vascular responses between AT1-AA and normal pregnant rats was abolished by ET(A) receptor blockade.
authors: Department of Obstetrics & Gynecology (Division of Maternal Fetal Medicine), University of Mississippi Medical Center, Jackson, Mississippi 39216-4505, USA.
authors: Marc R
authors: MR
authors: Parrish
authors: Michael J
authors: MJ
authors: Ryan
authors: Porter
authors: P
authors: Glover
authors: Justin
authors: J
authors: Brewer
authors: Lillian
authors: L
authors: Ray
authors: Ralf
authors: R
authors: Dechend
authors: James N
authors: JN
authors: Martin
authors: Babbette B
authors: BB
authors: Lamarca
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