title: Up-regulation of intrarenal renin-agiotensin system contributes to renal damage in high-salt induced hypertension rats.
abstract: OBJECTIVE
  To investigate the change of intrarenal renin-agiotensin system (RAS) and its role in high-salt induced hypertension.
  
  
  METHODS
  Wistar rats were divided into normal-salt (NS), high-salt diet (HS) and high-salt diet with Losartan group (HS+L), for 6 weeks. Systolic blood pressure (SBP) was monitored. Blood and urine samples were collected every 2 weeks. Angiotensinogen (AGT) was measured by ELISA. AGT mRNA and protein were measured by real-time PCR and immunohistochemistry. Renin activity and angiotensin II (Ang II) were measured by radioimmunoassay.
  
  
  RESULTS
  HS versus NS group, SBP increased from 2(nd) week (P<0.05), urinary protein increased at 6(th) week (P<0.05). Although plasma renin, AGT and Ang II had no significant changes (P>0.05), renal cortex renin, AGT, and Ang II increased significantly in HS (P<0.05). In HS+L, Losartan failed to reduce SBP (P>0.05) but abolished the increase of proteinuria (P<0.01), renal cortex renin, AGT, Ang II and urinary AGT reduced (P<0.05) while plasma renin, AGT and Ang II enhanced (P<0.05) when compared with HS. Urinary AGT was positively correlated with renal AGT (r=0.592, P <0.01) and Ang II (r=0.726, P <0.01).
  
  
  CONCLUSIONS
  Inappropriate response of the renal RAS to a high salt diet may contribute to hypertension and renal damage, and urinary AGT could reflect intrarenal RAS activity.
authors.affiliation: Department of Nephrology, Peking University Third Hospital, Beijing 100191, China.
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wu
authors.forename: Yaoxian
authors.initials: Y
authors.lastname: Liang
authors.forename: Yimu
authors.initials: Y
authors.lastname: Zheng
authors.forename: Qiong
authors.initials: Q
authors.lastname: Bai
authors.forename: Zheng
authors.initials: Z
authors.lastname: Zhuang
authors.forename: Lata
authors.initials: L
authors.lastname: A
authors.forename: Danxia
authors.initials: D
authors.lastname: Zheng
authors.forename: Yue
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000804:Angiotensin II / Q000097:blood; D047228:Angiotensin II Type 1 Receptor Blockers / Q000627:therapeutic use; D000808:Angiotensinogen / Q000378:metabolism; D000818:Animals; D004032:Diet; D006977:Hypertension, Renal / Q000139:chemically induced* / Q000473:pathology*; D007668:Kidney / Q000473:pathology*; D019808:Losartan / Q000627:therapeutic use; D008297:Male; D011507:Proteinuria / Q000139:chemically induced / Q000378:metabolism; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017208:Rats, Wistar; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System / Q000235:genetics*; D017673:Sodium Chloride, Dietary / Q000009:adverse effects*; D015854:Up-Regulation
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D012333:RNA, Messenger; D017673:Sodium Chloride, Dietary; D000808:Angiotensinogen; D000804:Angiotensin II; D012083:Renin; D019808:Losartan