title: Changes seen in the aging kidney and the effect of blocking the renin-angiotensin system.
abstract: BACKGROUND
  The objective was to evaluate structural changes of glomeruli during aging and the role of chronic renin-angiotensin system inhibition (RASi) on these changes; starting RASi on Wistar rats at two different moments: the first group after weaning and the second at the midpoint of their lifespan (12 months).
  
  
  METHODS
  Thirty rats were divided, after weaning, into three groups of 10: group 1: control (C); group 2 : 30 mg/kg/day losartan (L); group 3 : 10 mg/kg/day enalapril (E). At 18 months, rats were placed in metabolic cages to evaluate proteinuria, then killed. Another group of 24 rats, 12 months old, were divided into three groups of eight: group 1: C; group 2: L; group 3: E. At 18 months the same procedure described above was carried out. Finally, a third group of 20 rats was studied as healthy controls and killed: 10 rats at 7 months and ten at 12 months of age. Tissue samples were collected after sacrifice. To evaluate glomerular fibrotic changes, both focal and periglomerular sclerosis, and mesangial matrix expansion, a scoring scale was established. We also evaluated anti-alpha-SM-actin and anti-collagen-III immunolabeling. Glomerular area was measured using an image analyzer.
  
  
  RESULTS
  Proteinuria and serum creatinine increased with age but were reduced in treated animals. Main glomerular changes present in 18-month-old rats were reduced by half in treated animals. Glomerular area showed significant increase with normal aging and all treatment strategies protected against it.
  
  
  CONCLUSIONS
  RAS plays a central role in natural process of renal aging, probably by producing effects influencing the biology of aging, the effects of which can be attenuated by RASi.
authors: Institute of Cardiovascular Pathophysiology (INFICA), School of Medicine, University of Buenos Aires, Argentina.
authors: Felipe
authors: F
authors: Inserra
authors: Nidia
authors: N
authors: Basso
authors: Marcelo
authors: M
authors: Ferder
authors: Marcelo
authors: M
authors: Userpater
authors: Inés
authors: I
authors: Stella
authors: Nora
authors: N
authors: Paglia
authors: Pablo
authors: P
authors: Inserra
authors: David
authors: D
authors: Tenembaum
authors: León
authors: L
authors: Ferder
mesh_terms: D000199:Actins / Q000378:metabolism; D000367:Age Factors; D000375:Aging / Q000378:metabolism* / Q000473:pathology; D047228:Angiotensin II Type 1 Receptor Blockers / Q000494:pharmacology*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D015415:Biomarkers / Q000097:blood / Q000652:urine; D024061:Collagen Type III / Q000378:metabolism; D003404:Creatinine / Q000097:blood; D004656:Enalapril / Q000494:pharmacology*; D005355:Fibrosis; D007678:Kidney Glomerulus / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D019808:Losartan / Q000494:pharmacology*; D008297:Male; D011507:Proteinuria / Q000378:metabolism / Q000517:prevention & control; D051381:Rats; D017208:Rats, Wistar; D012084:Renin-Angiotensin System / Q000187:drug effects*; D014886:Weaning
chemical_list: D000199:Actins; D047228:Angiotensin II Type 1 Receptor Blockers; D000806:Angiotensin-Converting Enzyme Inhibitors; D015415:Biomarkers; D024061:Collagen Type III; D003404:Creatinine; D004656:Enalapril; D019808:Losartan; C498862:Acta2 protein, rat