Volume homeostasis in calves with artificial atria and ventricles
| Autor: | R. L. Baranowski, Gregory L. Burns, Jerry B. Riebman, Carl Kablitz, Frederic M. Birch, Don B. Olsen, Christof Westenfelder |
|---|---|
| Rok vydání: | 1990 |
| Předmět: |
Vasopressin
medicine.medical_specialty Cardiac output Time Factors Physiology Heart Ventricles Hypertension Pulmonary medicine.medical_treatment Plasma Substitutes Natriuresis Diuresis Heart Artificial Kidney Plasma renin activity chemistry.chemical_compound Atrial natriuretic peptide Internal medicine medicine Animals Homeostasis Heart Atria Saline Heart Failure Blood Volume Aldosterone business.industry Hemodynamics Hormones Endocrinology chemistry Potassium cardiovascular system Cattle business |
| Zdroj: | American Journal of Physiology-Renal Physiology. 258:F1005-F1017 |
| ISSN: | 1522-1466 1931-857X |
| DOI: | 10.1152/ajprenal.1990.258.4.f1005 |
| Popis: | We examined whether replacement of cardiac atria and ventricles with total artificial hearts (TAH), a procedure that removes cardiac nerves and all sources of atrial natriuretic factor (ANF), would cause alterations in volume homeostasis in awake calves. Preoperatively, extracted plasma immunoreactive (ir)ANF levels were 13.3 +/- 0.6 and remained postoperatively at 10.5 +/- 0.4 pg/ml (P less than 0.01). TAH implantation caused systemic and pulmonary hypertension (P less than 0.01), salt retention, edema, and significant elevations of plasma renin, aldosterone, and arginine vasopressin. In intact calves rapid infusion of 6 liters of normal saline raised irANF levels to 73.7 +/- 6.5 pg/ml (P less than 0.01) and elicited a large natriuresis and diuresis. No such response to 6 liters of normal saline was obtained after calves had recovered from TAH implantation. Reduction of cardiac output (CO) by 50% caused further salt retention and no change in irANF levels. Elevation of CO back to and 33% above base line produced only a diuresis, whereas salt retention persisted and irANF levels remained unchanged. The same maneuvers elicited in surgical control calves (artificial ventricles only, largely intact atria) a significant increase in irANF levels and a diuresis and natriuresis. In conclusion, alterations in volume homeostasis observed after TAH implantation seem to be the consequence of at least two pathophysiological mechanisms: 1) functional ANF "deficiency," characterized by apparently unregulated ANF secretion from noncardiac sites, and 2) cardiac denervation. |
| Databáze: | OpenAIRE |
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