Title

Comparison of hypoxia and ouabain effects on the myocardial uptake kinetics of technetium-99m hexakis 2-methoxyisobutyl isonitrile and thallium-201

UMMS Affiliation

Department of Radiology, Division of Nuclear Medicine

Date

9-1-1989

Document Type

Article

Subjects

Animals; Anoxia; Heart; Myocardium; Organometallic Compounds; Ouabain; Rabbits; Technetium; Technetium Tc 99m Sestamibi; Thallium Radioisotopes

Disciplines

Life Sciences | Medicine and Health Sciences

Abstract

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.

Rights and Permissions

Citation: J Nucl Med. 1989 Sep;30(9):1500-6.

Related Resources

Link to Article in PubMed

Journal Title

Journal of nuclear medicine : official publication, Society of Nuclear Medicine

PubMed ID

2527973