title: Urinary renin, but not angiotensinogen or aldosterone, reflects the renal renin-angiotensin-aldosterone system activity and the efficacy of renin-angiotensin-aldosterone system blockade in the kidney.
abstract: OBJECTIVE
  To study which renin-angiotensin-aldosterone system (RAAS) component best reflects renal RAAS activity.
  
  
  RESULTS
  We measured urinary and plasma renin, prorenin, angiotensinogen, aldosterone, albumin and creatinine in 101 diabetic and nondiabetic patients with or without hypertension. Plasma prorenin was elevated in diabetic patients. Urinary prorenin was undetectable. Urinary albumin and renin were higher in diabetic patients. Men had higher plasma renin/prorenin levels, and lower plasma angiotensinogen levels than women. Plasma creatinine and albumin were also higher in men. Urinary RAAS components showed no sexual dimorphism, whereas urinary creatinine and albumin were higher in men. Angiotensin-converting enzyme inhibitors and angiotensin II type 1 receptor blockers increased plasma renin and decreased plasma angiotensinogen, without altering plasma aldosterone. In contrast, in urine, these drugs decreased renin and aldosterone without affecting angiotensinogen. When analyzing all patients together, urinary angiotensinogen excretion closely mimicked that of albumin, whereas urinary angiotensinogen and albumin levels both were 0.05% or less of their concomitant plasma levels. This may reflect the identical glomerular filtration and tubular handling of both proteins, which have a comparable molecular weight. In contrast, urinary renin excretion did not correlate with urinary albumin excretion, and the urinary/plasma concentration ratio of renin was more than 200 times the ratio of albumin, despite its comparable molecular weight. Urinary aldosterone excretion closely followed urinary creatinine excretion.
  
  
  CONCLUSIONS
  The increased urinary renin levels in diabetes and the decreased urinary renin levels following RAAS blockade, occurring independently of changes in plasma renin, reflect the activated renal RAAS in diabetes and the success of RAAS blockade in the kidney, respectively. Urinary renin, therefore, more closely reflects renal RAAS activity than urinary angiotensinogen or aldosterone.
authors.affiliation: Division of Pharmacology and Vascular Medicine, Department of Internal Medicine, Erasmus MC, Rotterdam, The Netherlands.
authors.forename: Mieke
authors.initials: M
authors.lastname: van den Heuvel
authors.forename: Wendy W
authors.initials: WW
authors.lastname: Batenburg
authors.forename: Sjaam
authors.initials: S
authors.lastname: Jainandunsing
authors.forename: Ingrid M
authors.initials: IM
authors.lastname: Garrelds
authors.forename: Jeanette M G
authors.initials: JM
authors.lastname: van Gool
authors.forename: Richard A
authors.initials: RA
authors.lastname: Feelders
authors.forename: Anton H
authors.initials: AH
authors.lastname: van den Meiracker
authors.forename: A H Jan
authors.initials: AH
authors.lastname: Danser
mesh_terms: D000368:Aged; D000450:Aldosterone / Q000652:urine*; D000808:Angiotensinogen / Q000097:blood / Q000652:urine*; D003404:Creatinine / Q000652:urine; D003920:Diabetes Mellitus / Q000097:blood / Q000652:urine; D005260:Female; D005919:Glomerular Filtration Rate; D006801:Humans; D007668:Kidney / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D012083:Renin / Q000097:blood / Q000652:urine*; D012084:Renin-Angiotensin System; D012737:Sex Factors; D000092502:Renin Inhibitors
chemical_list: D000450:Aldosterone; D000808:Angiotensinogen; D003404:Creatinine; D012083:Renin; D000092502:Renin Inhibitors