Tc-99m-labeled endothelin derivative for imaging of experimentally inducedatherosclerosis

Objective: to characterize the potential of an endothelin derivative labele d with technetium-99m (Tc-99m) for the imaging of experimentally induced at herosclerosis. Methods: neointima of different cellularity and severity of stenosis was induced in 32 rabbits by balloon denudation followed by distin ct dietary regimens and drug application. Angiograms and scintigrams after injection of the Tc-99m-labeled endothelin derivative were obtained. The ao rta was dissected for auto radiography, sudan-III-staining, morphometry, an d immunohistology. Results: the lesions induced could be detected in vivo ( whole body scintigram) in all the animals 15 min after the injection of the Tc-99m endothelin derivative. Autoradiography revealed a strong relationsh ip between tracer accumulation and sudan-III-staining of lesions. Accumulat ion of the endothelin derivative correlated with the number of neointimal s mooth muscle cells (SMC), but not with the number of medial SMC, neointimal macrophages, and neointimal area. Conclusions: the results indicate that i n vivo imaging of atherosclerosis with an endothelin derivative is a feasib le method of detecting and characterizing atherosclerotic arterial wall les ions at early stages. (C) 2001 Elsevier Science Ireland Ltd. All rights res erved.