Abstract
Effects of urodilatin (5, 10, 20, and 40 ng. kg-1. min-1) infused over 2 h on separate study days were studied in eight normal subjects with use of a randomized, double-blind protocol. All doses decreased renal plasma flow (hippurate clearance, 13-37%) and increased fractional Li+ clearance (7-22%) and urinary Na+ excretion (by 30, 76, 136, and 99% at 5, 10, 20, and 40 ng. kg-1. min-1, respectively). Glomerular filtration rate did not increase significantly with any dose. The two lowest doses decreased cardiac output (7 and 16%) and stroke volume (10 and 20%) without changing mean arterial blood pressure and heart rate. The two highest doses elicited larger decreases in stroke volume (17 and 21%) but also decreased blood pressure (6 and 14%) and increased heart rate (15 and 38%), such that cardiac output remained unchanged. Hematocrit and plasma protein concentration increased with the three highest doses. The renin-angiotensin-aldosterone system was inhibited by the three lowest doses but activated by the hypotensive dose of 40 ng. kg-1. min-1. Plasma vasopressin increased by factors of up to 5 during infusion of the three highest doses. Atrial natriuretic peptide immunoreactivity (including urodilatin) and plasma cGMP increased dose dependently. The urinary excretion rate of albumin was elevated up to 15-fold (37 +/- 17 micrograms/min). Use of a newly developed assay revealed that baseline urinary urodilatin excretion rate was low (
| Original language | English |
|---|---|
| Journal | American Journal of Physiology: Regulatory, Integrative and Comparative Physiology |
| Volume | 276 |
| Issue number | 3 Pt 2 |
| Pages (from-to) | R684-95 |
| ISSN | 0363-6119 |
| Publication status | Published - Mar 1999 |
Keywords
- Absorption
- Adult
- Albuminuria
- Atrial Natriuretic Factor
- Cardiovascular System
- Diuresis
- Double-Blind Method
- Electrolytes
- Endocrine Glands
- Hemodynamics
- Humans
- Kidney
- Kidney Tubules
- Male
- Peptide Fragments
- Radioimmunoassay
- Reference Values
- Renal Circulation