Atrial natriuretic peptide decreases blood volume in intact and anephric rats

Conference · Wed Mar 05 04:00:00 EST 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:7024925

Trippodo, N C; Chien, Y W; Pegram, B L; Cole, F E; MacPhee, A A; Kardon, M B

Atrial natriuretic peptide (ANP) reportedly lowers atrial pressure and increases hematocrit, suggesting venodilation and/or decreased blood volume (BV). To examine these possibilities, rat ANP (99-126) was administered to Inactinanesthetized rats (313 +/- 9 g, +/- SE) at 0.5 ..mu..g/kg/min for 30 minutes. Urine flow increased by 0.05 ml/min (p < 0.001) during the last 15 minutes of infusion. Mean arterial pressure (MAP) and thoracic central venous pressure (CVP) decreased (p < 0.001) by 12 and 0.5 mmHg, respectively; hematocrit increased by 4.1 units (p < 0.001) and BV (/sup 51/Cr-RBC) decreased by 3.4 ml/kg (p < 0.001). Mean circulatory filling pressure, measured by inflating an intracardiac balloon to briefly stop the circulation, did not change. Distribution of BV between the thoracic and spanchnic organs (whole-animal freezing in liquid nitrogen) was not measurably altered. The results suggest that the decrease in CVP was related more to decreased BV than to venodilation. To investigate possible mechanisms for the decreased BV, the same dose of ANP was administered to anephric rats. MAP decreased by 8 mmHg (p < 0.001); hematocrit increased by 2.4 units (p < 0.001) and BV decreased by 1.7 ml/kg (p < 0.05). The results indicate that short-term administration of ANP decreases blood volume by causing intravascular fluid to shift into the interstitium as well as by inducing diuresis.

• Research Organization: Alton Ochsner Medical Foundation, New Orleans, LA
• OSTI ID: 7024925
• Report Number(s): CONF-8604222-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:4
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
550901 -- Pathology-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMALS
ARTERIES
BETA DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BLOOD COUNT
BLOOD PRESSURE
BLOOD VESSELS
BODY
BODY FLUIDS
CARDIOVASCULAR DISEASES
CARDIOVASCULAR SYSTEM
CHROMIUM 51
CHROMIUM ISOTOPES
DISEASES
ELECTRON CAPTURE RADIOISOTOPES
ERYTHROCYTES
EVEN-ODD NUCLEI
INTERMEDIATE MASS NUCLEI
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MATERIALS
NUCLEI
ORGANIC COMPOUNDS
ORGANS
PEPTIDES
PROTEINS
RADIOISOTOPES
RATS
RODENTS
TRACER TECHNIQUES
VASODILATION
VEINS
VERTEBRATES