Measurements of myocardial flow vs. extraction of rubidium under varying physiological conditions
The relationship between myocardial rubidium extraction (E) and flow (F) are well described by the single capillary model E = (1-exp(-PS/F)) with a permeability surface product PS = 0.87 cc/min/gm. Some effects of alkalosis and acidosis have been reported. Here the authors investigate the effects of dipyridamole, norepinephrine-atropine, exsanguination, pacing, ouabain and calcium on extraction using Rb-82 PET and Rb-86 acute studies with microspheres in dogs. Thoracotomies were performed for left atrial microsphere infusion. Anesthesia was by N/sub 2/O and methoxyflurane. The degree of exsanguination, drug levels administered and pacing rates were sufficient to produce flow modifications. Extraction was calculated by dividing FE from Rb observations by F from microsphere data. These results of extraction vs. flow do not show a significant dependence on the method used for flow modification. There was less than a 20% change in FE after an infusion of 0.04 mg/kg ouabain over 5 minutes in 3 replicate studies each on 4 dogs. An important finding not previously explained in flow vs. extraction studies is the occurrence of extraction values greater than 1.0 which is possible only if the distribution opportunities of small cations are greater than that of microspheres. This is equivalent to the well known hematocrit effect in small channels.
- Research Organization:
- Donner Lab., Univ. of California, Berkeley, CA
- OSTI ID:
- 6779259
- Report Number(s):
- CONF-840619-
- Journal Information:
- J. Nucl. Med.; (United States), Vol. 25:5; Conference: 31. annual meeting of the Society of Nuclear Medicine, Los Angeles, CA, USA, 5 Jun 1984
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DOGS
MYOCARDIUM
POSITRON COMPUTED TOMOGRAPHY
RADIOISOTOPE SCANNING
RUBIDIUM 82
DIAGNOSTIC USES
RUBIDIUM 86
ATROPINE
CALCIUM
EXTRACTION
LABELLING
MICROSPHERES
NITROGEN OXIDES
NORADRENALINE
OUABAIN
PERMEABILITY
PHYSIOLOGY
ADRENAL HORMONES
ALKALI METAL ISOTOPES
ALKALINE EARTH METALS
ALKALOIDS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BETA-PLUS DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
CHALCOGENIDES
COMPUTERIZED TOMOGRAPHY
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ELEMENTS
EMISSION COMPUTED TOMOGRAPHY
GLYCOSIDES
HEART
HORMONES
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
MAMMALS
METALS
MINUTES LIVING RADIOISOTOPES
MUSCLES
NEUROREGULATORS
NITROGEN COMPOUNDS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
ORGANS
OXIDES
OXYGEN COMPOUNDS
PARASYMPATHOLYTICS
RADIOISOTOPES
RUBIDIUM ISOTOPES
SEPARATION PROCESSES
STEROID HORMONES
STROPHANTHINS
SYMPATHOMIMETICS
TOMOGRAPHY
USES
VERTEBRATES
550602* - Medicine- External Radiation in Diagnostics- (1980-)
550601 - Medicine- Unsealed Radionuclides in Diagnostics