Comparison of hypoxia and ouabain effects on the myocardial uptake kinetics of technetium-99m hexakis 2-methoxyisobutyl isonitrile and thallium-201
- Univ. of Massachusetts Medical Center, Worcester (USA)
Effects of hypoxia and ouabain on transcapillary exchange of (99mTc)hexakis (2-methoxyisobutylisonitrile) (SESTAMIBI, also known as MIBI or HEXAMIBI) and 201TI were investigated with indicator-dilution studies using isolated rabbit hearts. Peak myocardial extraction (Emax), permeability-surface area products (PScap), and net myocardial extraction (Enet) were compared among serial injections during constant coronary flows. Overall, measures of transcapillary transport (Emax and PScap) for SESTAMIBI were significantly lower (p less than 0.001) than those simultaneously determined for thallium, but estimates of tissue retention (Enet) for SESTAMIBI and thallium were not statistically distinguishable. Hypoxia had no significant effect on mean (+/- s.d.) Emax for SESTAMIBI (0.31 +/- 0.13) or thallium (0.59 +/- 0.11), nor on mean PScap or Enet values. Ouabain (1.5 X 10(-7) M and 1.5 X 10(-6) M) had no effect on SESTAMIBI or thallium Emax (respectively, 0.29 +/- 0.08 and 0.60 +/- 0.05) or on PScap for SESTAMIBI. Thallium PScap was depressed with higher ouabain dose (control, 1.22 +/- 0.40; high ouabain, 1.06 +/- 0.41 ml/min/g; p less than 0.01). Ouabain also caused a significant and progressive increase in average SESTAMIBI Enet (control, 0.23 +/- 0.10 to high ouabain, 0.33 +/- 0.12; p less than 0.05), but depressed thallium Enet (control, 0.38 +/- 0.14 to high ouabain, 0.32 +/- 0.18; p less than 0.01). These results suggest myocardial metabolic and/or functional status have minor influence on transcapillary transport of SESTAMIBI and thallium, but significantly affects cellular retention.
- OSTI ID:
- 5362159
- Journal Information:
- Journal of Nuclear Medicine; (USA), Vol. 30:9; ISSN 0161-5505
- Country of Publication:
- United States
- Language:
- English
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ANOXIA
BIOLOGICAL EFFECTS
OUABAIN
RADIOPHARMACEUTICALS
TISSUE DISTRIBUTION
COMPARATIVE EVALUATIONS
HEART
IN VITRO
MYOCARDIUM
RABBITS
TECHNETIUM 99
THALLIUM 201
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
CARBOHYDRATES
CARDIAC GLYCOSIDES
CARDIOTONICS
CARDIOVASCULAR AGENTS
CARDIOVASCULAR SYSTEM
DAYS LIVING RADIOISOTOPES
DISTRIBUTION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
GLYCOSIDES
HEAVY NUCLEI
HOURS LIVING RADIOISOTOPES
INTERMEDIATE MASS NUCLEI
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MUSCLES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
RADIOISOTOPES
SECONDS LIVING RADIOISOTOPES
STROPHANTHINS
TECHNETIUM ISOTOPES
THALLIUM ISOTOPES
VERTEBRATES
YEARS LIVING RADIOISOTOPES
550601* - Medicine- Unsealed Radionuclides in Diagnostics