Comparison of the effects of ANF 99-126 and ANF 103-126 on captopril-induced renin release in man.
OBJECTIVE
The aim was to examine the effects of atrial natriuretic factor (ANF) 99-126 and ANF 103-126, an N-terminal shortened analogue of the peptide, on the plasma renin activity response to captopril, an inhibitor of angiotensin-converting enzyme.


METHODS
Two protocols were performed. In the first protocol, subjects were studied on three occasions. Captopril 25 mg was given and a 60 minute infusion of 5% D-glucose (placebo), or ANF 99-126 3 or 10 pmol/kg/min, was administered in a single blind randomized manner. The second protocol was divided in two parallel phases comparing ANF 103-126 either 3 or 10 pmol/kg/min to placebo.


METHODS
Thirty-three salt-replete healthy male volunteers aged 21-39 years were studied in the supine position.


METHODS
Plasma renin activity, plasma ANF 99-126 and ANF 103-126 levels, heart rate and blood pressure were measured.


RESULTS
Compared to placebo infusion, the rise in plasma renin activity after captopril was attenuated by ANF 99-126 infusion (from 755% of baseline to 294% by ANF 99-126 3 pmol/kg/min and from 755 to 202% by 10 pmol/kg/min; P less than 0.03 and P less than 0.01 respectively). The comparable findings with ANF 103-126 were 492 to 218% (3 pmol/kg/min) and 645 to 364% (10 pmol/kg/min) (P less than 0.01 and P less than 0.01 respectively).


CONCLUSIONS
The results, taken in conjunction with previous findings, suggest that atrial natriuretic factor inhibits in a non-selective manner the renin response to all secretagogues so far tested in man. The current results also suggest that the anti-renin action of atrial natriuretic factor does not depend on the first four N-terminal amino acids of the native peptide.
Lang
C C
CC
Department of Clinical Pharmacology, Ninewells Hospital and Medical School, Dundee, UK.
McMurray
J J
JJ
Moyses
C
C
Struthers
A D
AD
D000328:Adult; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002216:Captopril / Q000494:pharmacology*; D003864:Depression, Chemical; D004232:Diuretics / Q000494:pharmacology*; D006801:Humans; D008297:Male; D010446:Peptide Fragments / Q000494:pharmacology*; D012083:Renin / Q000097:blood / Q000378:metabolism*; D016037:Single-Blind Method; D013484:Supination
D004232:Diuretics; D010446:Peptide Fragments; C062525:atrial natriuretic factor prohormone (103-126); D009320:Atrial Natriuretic Factor; D002216:Captopril; D012083:Renin