Response of urinary angiotensin to challenges of the renin-angiotensin system

Clin Chim Acta. 1991 Jun 14;199(2):195-204. doi: 10.1016/0009-8981(91)90111-o.

Abstract

Angiotensin has an intrarenal action which may not parallel its action in the general circulation. We investigated whether the urinary excretion rates of angiotensin I and II (UV-AI, UV-AII) can be used as a marker of renal production. We therefore measured UV-AI, UV-AII, plasma angiotensin I and II (PAI, PAII), and plasma renin activity (PRA) in healthy subjects under conditions influencing the renin-angiotensin system: captopril injection (n = 7), enalapril treatment (n = 9), furosemide infusion on high and low sodium intake (n = 6), indomethacin treatment (n = 8), and head-out water immersion (three sodium intakes). After captopril (acute) and enalapril (chronic), PAI and PRA increased, PAII decreased, but neither UV-AI nor UV-AII changed. During furosemide infusion, PAI, PAII, PRA, as well as UV-AI and UV-AII increased. During indomethacin treatment, PAI, PAII, and PRA decreased, whereas UV-AI and UV-AII did not change consistently. Sodium restriction increased PAI, PAII, and PRA, but did not alter UV-AI and UV-AII. Head-out immersion decreased PAI, PAII, and PRA, but did not change UV-AI and UV-AII. The relative constancy of the urinary AI and AII excretion rates makes it doubtful whether urinary angiotensins reflect changes of renal angiotensin production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Angiotensin I / blood
  • Angiotensin I / urine*
  • Angiotensin II / blood
  • Angiotensin II / urine*
  • Captopril / pharmacology
  • Enalapril / pharmacology
  • Female
  • Furosemide / pharmacology
  • Humans
  • Immersion / physiopathology
  • Indomethacin / pharmacology
  • Male
  • Renin / blood
  • Renin-Angiotensin System / drug effects
  • Renin-Angiotensin System / physiology*
  • Sodium, Dietary / administration & dosage

Substances

  • Sodium, Dietary
  • Angiotensin II
  • Enalapril
  • Furosemide
  • Angiotensin I
  • Captopril
  • Renin
  • Indomethacin