title: Role of Angiotensin Type 2 Receptor on Nitric Oxide Production Response to Angiotensin II Administration in Ovariectomised Rats Treated with Estradiol.
abstract: BACKGROUND
  Renin-angiotensin system activity is gender related. The vasodilatory response of angiotensin II (AngII) angiotensin type 2 receptor (AT2R) may involve nitric oxide (NO) production. We attempted to find the role of AT2R on NO formation response to AngII administration in ovariectomised rats treated with estradiol (OVE).
  
  
  METHODS
  A total of 33 female Wistar rats were divided into 3 groups; intact animals, ovariectomised treated with placebo (OVX) and OVE. At 2 weeks later, all animals were subjected to anesthetize and catheterize and each group was divided into two subgroups that received AT2R antagonist (PD123319) or vehicle. Each animal was subjected to 1 h continuous infusion of AngII (~20 μg/kg/h) and the level of NO metabolite (nitrite) was measured before and after AngII infusion.
  
  
  RESULTS
  At the presence of AT2R, the serum level of nitrite in response to AngII administration in OVE groups increased significantly (P < 0.05).
  
  
  CONCLUSIONS
  However, this increase was abolished by AT2R antagonist. It seems that AT2R involves nitrite production response to AngII in OVE.
authors.affiliation: Department of Physiology, Zahedan University of Medical Sciences, Zahedan, Iran.
authors.forename: Tahereh
authors.initials: T
authors.lastname: Safari
authors.affiliation: Water and Electrolytes Research Center, Isfahan University of Medical Sciences, Isfahan, Iran ; Department of Physiology, Isfahan University of Medical Sciences, Isfahan, Iran ; Isfahan Institute of Basic and Applied Sciences Research, Isfahan, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Nematbakhsh
keywords: Angiotensin receptor; estradiol; nitrite; renin-angiotensin system