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Hemodilution mediates hemodynamic changes during acute expansion in unanesthetized rats
- Source :
- American Journal of Physiology-Regulatory, Integrative and Comparative Physiology. 279:R2243-R2251
- Publication Year :
- 2000
- Publisher :
- American Physiological Society, 2000.
-
Abstract
- Studies were carried out to determine the relative importance of volume and hemodilution on hemodynamic adjustments to acute volume expansion. Systemic and renal hemodynamics were monitored in unanesthetized and unrestrained rats during progressive and equivalent blood volume expansion with saline (Sal; 1, 2, and 4% body wt), 7% BSA solution (0.35, 0.7, and 1.4% body wt), and reconstituted whole blood from donor rats (WBL; 0.35, 0.7, and 1.4% body wt). Mean arterial pressure remained unchanged in Sal and BSA but increased progressively in WBL-expanded rats (from 92 to 106 mmHg after maximal expansion). In Sal and BSA-expanded rats, cardiac output (CO) and renal blood flow (RBF) increased (CO: Sal from 19 to 20, 22, and 25; BSA from 21 to 23, 27, and 31; RBF: Sal from 1.6 to 1.8, 2.2, and 2.5; BSA from 2 to 2.4, 2.7, and 3.1 ml · min−1 · 100 g body wt−1), whereas total peripheral (TPR) and renal vascular (RVR) resistance decreased in parallel with the expansions. After expansion with WBL, CO increased progressively but less extensively than in cell-free expanded rats (21 to 22, 24, and 26 ml · min−1 · 100 g body wt−1), whereas TPR and RVR remained unchanged. Systemic hematocrit (Hct) decreased approximately the same after expansion with Sal or BSA solutions but remained unchanged after expansion with WBL. Isovolemic hemodilution to Hct levels comparable to those seen after maximal expansion with cell-free solutions also reduced SVR and RVR, although less extensively. These findings suggest that in unanesthetized rats hemodilution plays a major role in the systemic and renal hemodynamics during expansion.
- Subjects :
- Male
Physiology
Partial Pressure
Plasma Substitutes
Hemodynamics
Blood Pressure
Blood volume
Vasodilation
Renal Circulation
Physiology (medical)
Volume expansion
Animals
Medicine
Renal hemodynamics
Cardiac Output
Rats, Wistar
Hemodilution
business.industry
Body Weight
Blood flow
Carbon Dioxide
Rats
Oxygen
Blood pressure
medicine.anatomical_structure
Hematocrit
Anesthesia
Vascular resistance
Vascular Resistance
business
Subjects
Details
- ISSN :
- 15221490 and 03636119
- Volume :
- 279
- Database :
- OpenAIRE
- Journal :
- American Journal of Physiology-Regulatory, Integrative and Comparative Physiology
- Accession number :
- edsair.doi.dedup.....1b163b2437181cc938a6d34663030086
- Full Text :
- https://doi.org/10.1152/ajpregu.2000.279.6.r2243