The in vivo cardiac kinetics of Tc-99m N-NOET are accelerated in obese, hyperlipidemic Zucker rats.
BACKGROUND
Previous studies demonstrated that the intrinsic myocardial washout of bis(N-ethoxy,N-ethyldithiocarbamato)nitrido technetium(V) (technetium 99m N-NOET) was affected by changes occurring in the intravascular compartment such as variations in circulating lipid levels. We sought to determine whether the myocardial kinetics of Tc-99m N-NOET were affected by hyperlipidemia in a clinically relevant experimental model.


RESULTS
Tc-99m N-NOET (50 MBq/kg) and thallium 201 (12 MBq/kg) were injected intravenously into hyperlipidemic fa/fa Zucker rats (n=6) and their lean, normolipidemic littermates (n=8), and dual-isotope in vivo planar imaging was performed for 60 minutes. In vivo image quantification indicated significantly faster cardiac washout of Tc-99m N-NOET in fa/fa animals versus lean animals (time constant, 411+/-64 minutes vs 1094+/-226 minutes, respectively; P<.05), whereas Tl-201 cardiac washout was not affected (356+/-85 minutes vs 337+/-53 minutes, respectively; P=not significant).


CONCLUSIONS
The cardiac kinetics of Tc-99m N-NOET, but not those of Tl-201, were accelerated after intravenous injection of the tracer in fa/fa Zucker rats with circulating lipid levels similar to those encountered clinically in hyperlipidemic patients. The relationship between lipidemia and the rate of Tc-99m N-NOET myocardial washout warrants further clinical investigation.
Riou
Laurent M
LM
INSERM 0340 Radiopharmaceutiques Biocliniques, Université de Grenoble, Grenoble, France. Laurent.Riou@ujf-grenoble.fr
Broisat
Alexis
A
Dimastromatteo
Julien
J
Vanzetto
Gérald
G
Fagret
Daniel
D
Ghezzi
Catherine
C
D000818:Animals; D006321:Heart / Q000000981:diagnostic imaging; D006949:Hyperlipidemias / Q000150:complications / Q000000981:diagnostic imaging* / Q000378:metabolism*; D007700:Kinetics; D008657:Metabolic Clearance Rate; D009206:Myocardium / Q000378:metabolism*; D009765:Obesity / Q000150:complications / Q000000981:diagnostic imaging* / Q000378:metabolism*; D009928:Organ Specificity; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D011924:Rats, Zucker; D013851:Thinness / Q000150:complications / Q000000981:diagnostic imaging / Q000378:metabolism; D013859:Thiocarbamates / Q000493:pharmacokinetics*; D014018:Tissue Distribution
D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; D013859:Thiocarbamates; C093922:technetium Tc 99m, bis(N-ethoxy-N-ethyldithiocarbamato)nitrido-