No effect of short term angiotensin II infusion on plasma renin substrate levels in man.
We studied the effect of angiotensin II (A-II) infusion (4 ng/kg BW.min) on plasma renin substrate (RS) levels and PRA in five normal men during normal, diuretic-stimulated, and enalapril-interrupted function of the renin-angiotensin system. A-II infusion increased (15-25%) both systolic and diastolic blood pressure in the normal state and during angiotensin-converting enzyme inhibition, whereas the increase during diuretic-stimulated renin-angiotensin system function was less. The plasma RS concentration was measured by both direct and indirect RIA. The mean basal plasma RS levels, measured with direct assay, were 1516 +/- 150 (SE) in the normal state, 1566 +/- 150 after diuretic administration, and 1650 +/- 133 nmol/L after enalapril administration. The corresponding mean basal plasma RS levels measured with the indirect assay were 1073 +/- 100, 1031 +/- 57, and 902 +/- 78 nmol/L, respectively. Plasma RS levels did not change during or after the A-II infusions, whereas PRA decreased significantly in all experimental conditions. The results suggest that A-II exerts no direct stimulatory effect on hepatic release of RS. Thus, A-II appears not to be important in the short term regulation of plasma RS levels.
Metsärinne
K
K
Unit of Clinical Physiology, Minerva Foundation Institute for Medical Research, Helsinki, Finland.
Fyhrquist
F
F
Tötterman
J
J
Tikkanen
I
I
D000328:Adult; D000804:Angiotensin II / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002800:Cholinesterase Inhibitors / Q000097:blood; D004232:Diuretics / Q000494:pharmacology; D004656:Enalapril / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D006339:Heart Rate / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008297:Male; D008875:Middle Aged; D012083:Renin / Q000097:blood*; D012084:Renin-Angiotensin System / Q000187:drug effects
D002800:Cholinesterase Inhibitors; D004232:Diuretics; D000804:Angiotensin II; D004656:Enalapril; D012083:Renin; D005947:Glucose