Interactions of physiological and pharmacological concentrations of ANP and angiotensin II in conscious dogs.
This study in conscious, chronically instrumented dogs investigated the effects of human atrial natriuretic peptide [hANP-(99-126)] at physiological (5 ng.kg-1.min-1) and pharmacological (5-900 ng.kg-1.min-1) doses on angiotensin II (ANG II)-mediated effects on hemodynamics, renal excretion, and aldosterone release. Five female beagle dogs kept chronically on a dietary sodium intake of 2.5 mmol Na.kg body wt-1.day-1 received an intravenous infusion of 1, 4, 10, 20, and 50 ng.kg-1.min-1 ANG II (20-min periods) without (protocol 1) or with (protocol 2) simultaneous intravenous infusion of 5 ng.kg-1.min-1 hANP-(99-126). In protocol 1, glomerular filtration rate (means +/- SD) decreased from 4.0 +/- 0.6 to 2.8 +/- 0.5 ml.kg-1.min-1, renal sodium excretion (UNaV) decreased from 2.8 +/- 1.6 to 0.4 +/- 0.2 mumol.kg-1.min-1, and urine volume (V) decreased from 45 +/- 23 to 6 +/- 8 microliters.kg-1.min-1. There were no differences in the values between protocol 1 and protocol 2. Mean arterial blood pressure (MABP) increased similarly from 118 +/- 16 to 166 +/- 9 mmHg in protocol 1 and from 109 +/- 11 to 162 +/- 7 mmHg in protocol 2. Maximal aldosterone secretion was stimulated less in protocol 2 (481 +/- 92 vs. 362 +/- 158 pg/ml; P less than 0.05). In ANG II-pretreated (20 ng.kg-1.min-1) dogs (n = 4; protocol 3), intravenous hANP-(99-126) doses of 300-900 ng.kg-1.min-1 decreased MABP and central venous pressure.(ABSTRACT TRUNCATED AT 250 WORDS)
Kuhlen
R
R
Department of Anesthesiology and Operative Intensive Medicine, Universitätsklinikum Rudolf Virchow Standort Charlottenburg, Freie Universität Berlin, Germany.
Seibt
H
H
Engel
R
R
Kaczmarczyk
G
G
D000450:Aldosterone / Q000097:blood; D000804:Angiotensin II / Q000097:blood / Q000494:pharmacology*; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000097:blood / Q000494:pharmacology*; D004285:Dogs; D004347:Drug Interactions; D005260:Female; D006439:Hemodynamics / Q000187:drug effects; D007668:Kidney / Q000378:metabolism; D009994:Osmolar Concentration
D000804:Angiotensin II; D000450:Aldosterone; D009320:Atrial Natriuretic Factor