Effects of isoproterenol on distribution of perfusion in embolized dog lungs
In 19 mechanically ventilated, anesthetized dogs, autologous venous thrombi were formed in the inferior vena cava and subsequently released. Serial perfusion lung scintigrams revealed the postembolic distribution of pulmonary blood flow before, during, and after the infusion of isoproterenol at 2.2 ..mu..g/min. Isoproterenol failed to restore perfusion to embolically occluded regions. When reperfusion occurred it was attributable to clot resolution. Gas exchange and hemodynamic measurements obtained in seven thromboembolized animals showed no scan evidence of reperfusion during the isoproterenol infusion. After embolization, cardiac output increased from 1.7 to 2.6 liter/min (p < 0.05), and P anti ..nu..O/sub 2/ from 38.0 to 45.3 mm Hg (p < 0.05). Shunt fraction remained unchanged. The postembolic infusion of isoproterenol was associated with a further increase in cardiac output to 3.6 liter/min (p < 0.01), an elevation in P anti ..nu..O/sub 2/ to 50.7 mm Hg, along with a decrease in pulmonary vascular resistance from the postembolic mean of 448 to 246 dynes.sec.cm/sup -5/ (p < 0.05). Perfusion defects following acute pulmonary thromboembolization are not altered by the infusion of the potent pulmonary vasodilator, isoproterenol. Infusion of this drug following thromboembolization may have potential therapeutic benefit by reducing pulmonary vascular resistance, increasing cardiac output, and elevating the mixed-venous oxygen tension.
- Research Organization:
- Univ. of California, San Diego
- OSTI ID:
- 5707053
- Journal Information:
- J. Nucl. Med.; (United States), Vol. 20:9
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
EMBOLI
DIAGNOSIS
LUNGS
SCINTISCANNING
SYMPATHOMIMETICS
BIOLOGICAL EFFECTS
THROMBOSIS
ALBUMINS
BLOOD FLOW
DOGS
EXPERIMENTAL DATA
ISOLATED VALUES
MICROSPHERES
PERFUSED TISSUES
TECHNETIUM 99
THERAPY
VASODILATION
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARDIOVASCULAR DISEASES
COUNTING TECHNIQUES
DATA
DATA FORMS
DIAGNOSTIC TECHNIQUES
DISEASES
DRUGS
HOURS LIVING RADIOISOTOPES
INFORMATION
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAMMALS
NUCLEI
NUMERICAL DATA
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOISOTOPE SCANNING
RADIOISOTOPES
RESPIRATORY SYSTEM
TECHNETIUM ISOTOPES
TISSUES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics
550901 - Pathology- Tracer Techniques