title: Losartan attenuates vascular remodeling of the aorta in spontaneously hypertensive rats and the underlying mechanism.
abstract: OBJECTIVE
  To determine the effect of losartan on vascular remodeling and the underlying mechanism in spontaneously hypertensive rats(SHR).
  
  
  METHODS
  SHR of 12 weeks old were given losartan orally [0, 15, 30 mg/(kg.d), n=12]. The tail arterial pressure was measured every week. Eight weeks later, the pathological changes and p22(phox) expression in the thoracic aorta, the activity of catalase (CAT), the contents of H(2)O(2) and Ang II in the plasma were evaluated.
  
  
  RESULTS
  Blood pressure was increased in the SHR accompanied by the thickened wall and increased p22(phox) expression in the thoracic aorta. The plasma levels of H(2)O(2) and Ang II were elevated while the CAT level was decreased in the SHR. Administration of losartan reversed the thickened wall and increased the CAT activity concomitantly with the decreased plasma levels of H(2)O(2) and p22(phox) expression in the SHR. The plasma level of Ang II increased after the losartan treatment.
  
  
  CONCLUSIONS
  Oxidative stress induces the vascular remodeling of the aorta in the SHR. Losartan can reverse the vascular remodeling through down-regulating p22(phox) expression and inhibiting the oxidative stress.
authors.affiliation: Department of Cardiology, Xiangya Hospital, Central South University, Changsha 410008, China.
authors.forename: Fangxiong
authors.initials: F
authors.lastname: Li
authors.forename: Ruizheng
authors.initials: R
authors.lastname: Shi
authors.forename: Meichun
authors.initials: M
authors.lastname: Liao
authors.forename: Jianzhe
authors.initials: J
authors.lastname: Li
authors.forename: Shixun
authors.initials: S
authors.lastname: Li
authors.forename: Wei
authors.initials: W
authors.lastname: Pan
authors.forename: Tianlun
authors.initials: T
authors.lastname: Yang
authors.forename: Guogang
authors.initials: G
authors.lastname: Zhang
mesh_terms: D000804:Angiotensin II / Q000097:blood; D000818:Animals; D000959:Antihypertensive Agents / Q000494:pharmacology / Q000627:therapeutic use*; D001011:Aorta / Q000473:pathology* / Q000503:physiopathology; D002374:Catalase / Q000378:metabolism; D006861:Hydrogen Peroxide / Q000097:blood; D006973:Hypertension / Q000188:drug therapy* / Q000473:pathology* / Q000503:physiopathology; D019808:Losartan / Q000494:pharmacology / Q000627:therapeutic use*; D008297:Male; D019255:NADPH Oxidases / Q000378:metabolism; D018384:Oxidative Stress / Q000187:drug effects*; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY
chemical_list: D000959:Antihypertensive Agents; D000804:Angiotensin II; D006861:Hydrogen Peroxide; D002374:Catalase; D019255:NADPH Oxidases; C515768:Cyba protein, rat; D019808:Losartan