Infusion of iso-rANP(1-45) or (17-45) increases plasma immunoreactive ANP and lowers plasma renin activity and aldosterone.
We have reported that a second rat atrial natriuretic peptide, iso-rANP (1-45), as well as the putative ANP homologue, iso-rANP (17-45), elicited circulatory and renal responses in the rat similar to those found after administration of ANP. Iso-rANP also interacted with ANP to potentiate the observed biological activity in the rat. In the present studies in awake dogs, intravenous infusion of low doses (6.3-50 pmol.kg-1.min-1) of iso-rANP(1-45) and iso-rANP(17-45) increased plasma immunoreactive ANP and suppressed plasma renin activity (PRA) and aldosterone. Iso-rANP, like ring-deleted analogues of ANP, may have displaced ANP from ANP clearance receptors to increase plasma ANP concentration, since factors influencing myocardial ANP release were not changed. The effect of iso-rANP (1-45) and (17-45) in lowering PRA and plasma aldosterone may therefore have been indirect, via ANP stimulation of active guanylate cyclase-linked ANP receptors. However, an additional direct effect of iso-rANP on an active receptor cannot be excluded.
Jennings
D B
DB
Department of Physiology, Queen's University, Kingston, Ont., Canada.
McKirdy
J C
JC
Ohtake
P J
PJ
Sarda
I R
IR
Flynn
T G
TG
Hira
G K
GK
D000450:Aldosterone / Q000097:blood*; D000595:Amino Acid Sequence; D000818:Animals; D001127:Arginine Vasopressin / Q000097:blood; D009320:Atrial Natriuretic Factor / Q000097:blood* / Q000494:pharmacology*; D004285:Dogs; D005260:Female; D008297:Male; D008969:Molecular Sequence Data; D009994:Osmolar Concentration; D010446:Peptide Fragments / Q000494:pharmacology*; D012083:Renin / Q000097:blood*; D012964:Sodium / Q000097:blood
D010446:Peptide Fragments; C067014:iso-atrial natriuretic peptide (17-45); D001127:Arginine Vasopressin; C062794:iso-atrial natriuretic peptide; D000450:Aldosterone; D009320:Atrial Natriuretic Factor; D012964:Sodium; D012083:Renin