Comparative study of iodine-123-labeled hypericin and (99m)Tc-labeled hexakis [2-methoxy isobutyl isonitrile] in a rabbit model of myocardial infarction.
J Cardiovasc Pharmacol
; 62(3): 304-11, 2013 Sep.
Article
en En
| MEDLINE
| ID: mdl-23714775
ABSTRACT
Identification of myocardial infarction (MI) by imaging is critical for clinical management of ischemic heart disease. Iodine-123-labeled hypericin (¹²³I-Hyp) is a new potent infarct avid agent. We sought to compare target selectivity and organ distribution between ¹²³I-Hyp and the myocardial perfusion agent, technetium-99m-labeled hexakis [2-methoxy isobutyl isonitrile] ((99m)Tc-Sestamibi) in rabbits with acute MI. Hypericin was radiolabeled with I using iodogen as oxidant, and (99m)Tc-Sestamibi was prepared from a commercial kit and radioactive sodium pertechnetate. Rabbits (n = 6) with 24-hour-old MI received ¹²³I-Hyp intravenously and received (99m)Tc-Sestamibi 9 hours later. They were studied by dual-isotope simultaneous acquisition micro single photon emission computed tomography/computed tomography (DISA-µSPECT/CT), tissue gamma counting (TGC), autoradiography, and histology. After purification, ¹²³I-Hyp was obtained with radiochemical purity around 99%. DISA-µSPECT/CT images showed ¹²³I-Hyp retention in infarcted but not in normal myocardium. By TGC, accumulation values reached 1.175 ± 0.096 percentage of injected dose per gram (%ID/g) and 0.028 ± 0.007%ID/g in infarcted myocardium and normal myocardium with high tracer concentration in liver, intestines, and gallbladder. (99m)Tc-Sestamibi was prepared with radiochemical purity over 95%. DISA-µSPECT/CT showed no accumulation in MI and high initial radioactivity levels in normal myocardium that were rapidly cleared as confirmed by TGC (0.011 ± 0.003%ID/g). Liver and intestines were clearly visualized. By TGC, gallbladder and kidneys show moderate (99m)Tc-Sestamibi uptake. The selectivity of ¹²³I-Hyp for infarcted myocardium and (99m)Tc-Sestamibi for normal myocardium was confirmed. ¹²³I-Hyp distribution in rabbits is characterized by hepatobiliary excretion. (99m)Tc-Sestamibi undergoes hepatorenal elimination.
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Perileno
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Tecnecio Tc 99m Sestamibi
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Radiofármacos
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Vasos Coronarios
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Modelos Animales de Enfermedad
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Corazón
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Infarto del Miocardio
Límite:
Animals
Idioma:
En
Revista:
J Cardiovasc Pharmacol
Año:
2013
Tipo del documento:
Article
País de afiliación:
Bélgica