Response of urinary angiotensin to challenges of the renin-angiotensin system.
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.
Boer
P
P
Department of Nephrology and Hypertension, University Hospital, Utrecht, The Netherlands.
Vos
P F
PF
Koomans
H A
HA
Rabelink
A J
AJ
Beutler
J J
JJ
Dorhout Mees
E J
EJ
D000328:Adult; D000803:Angiotensin I / Q000097:blood / Q000652:urine*; D000804:Angiotensin II / Q000097:blood / Q000652:urine*; D002216:Captopril / Q000494:pharmacology; D004656:Enalapril / Q000494:pharmacology; D005260:Female; D005665:Furosemide / Q000494:pharmacology; D006801:Humans; D007101:Immersion / Q000503:physiopathology; D007213:Indomethacin / Q000494:pharmacology; D008297:Male; D012083:Renin / Q000097:blood; D012084:Renin-Angiotensin System / Q000187:drug effects / Q000502:physiology*; D012982:Sodium, Dietary / Q000008:administration & dosage
D012982:Sodium, Dietary; D000804:Angiotensin II; D004656:Enalapril; D005665:Furosemide; D000803:Angiotensin I; D002216:Captopril; D012083:Renin; D007213:Indomethacin