The effects of human atrial 28-amino acid peptide on systemic and renal hemodynamics in anesthetized rats.
The effects of synthetic human atrial 28-amino acid peptide (alpha-human atrial polypeptide) on systemic and renal hemodynamics were examined in two separate groups of Inactin-anesthetized rats. First, mean arterial pressure, heart rate, and cardiac output were measured before and during infusion of the peptide at rates of 0.04-0.67 microgram/kg per min. Cardiac output was determined by the dye-dilution method with a microcuvette inserted into a carotid-femoral arterial shunt. After 10 minutes of infusion, mean arterial pressure, cardiac output, and total peripheral resistance were reduced in a dose-dependent manner by 21% (P less than 0.001), 9% (P less than 0.05), and 11% (P less than 0.05), respectively, with 0.67 microgram/kg per min of alpha-human atrial natriuretic polypeptide. Despite the marked fall in blood pressure, the heart rate did not change. Second, urine volume, urinary sodium excretion, glomerular filtration rate ([3H]inulin clearance) and renal blood flow ([14C]p-aminohippuric acid sodium clearance and hematocrit) were measured. Increases in urine volume, urinary sodium excretion, filtration fraction, and fractional sodium excretion and a decrease in renal vascular resistance were dose dependent: +490% (P less than 0.01), +1340% (P less than 0.01), +19% (P less than 0.05), +1160% (P less than 0.01), and -18% (P less than 0.05), respectively, with 0.67 microgram/kg per min of alpha-human atrial natriuretic polypeptide. The glomerular filtration rate increased with 0.33 and 0.67 microgram/kg per min of alpha-human atrial natriuretic polypeptide (both P less than 0.05), whereas renal blood flow did not change.(ABSTRACT TRUNCATED AT 250 WORDS)
Hirata
Y
Y
Ishii
M
M
Sugimoto
T
T
Matsuoka
H
H
Sugimoto
T
T
Kangawa
K
K
Matsuo
H
H
D000758:Anesthesia; D000818:Animals; D009320:Atrial Natriuretic Factor / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D002302:Cardiac Output / Q000187:drug effects; D004231:Diuresis / Q000187:drug effects; D005919:Glomerular Filtration Rate / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D007668:Kidney / Q000098:blood supply*; D007700:Kinetics; D008297:Male; D009318:Natriuresis / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012079:Renal Circulation / Q000187:drug effects; D013874:Thiopental / Q000031:analogs & derivatives
C004316:thiobutabarbital; D009320:Atrial Natriuretic Factor; D013874:Thiopental