Detection of cardiomyopathy in an animal model using quantitative autoradiography

A fatty acid analog (15-p-iodophenyl)-3,3 dimethyl-pentadecanoic acid (DMIPP) was studied in cardiomyopathic (CM) and normal age-matched Syrian hamsters. Dual tracer quantitative wholebody autoradiography (QARG) with DMIPP and 2-[14C(U)]-2-deoxy-2-fluoro-D-glucose (FDG) or with FDG and 201Tl enabled comparison of the uptake of a fatty acid and a glucose analog with the blood flow. These comparisons were carried out at the onset and mid-stage of the disease before congestive failure developed. Groups of CM and normal animals were treated with verapamil from the age of 26 days, before the onset of the disease for 41 days. In CM hearts, areas of decreased DMIPP uptake were seen. These areas were much larger than the decrease in uptake of FDG or 201Tl. In early CM only minimal changes in FDG or 201Tl uptake were observed as compared to controls. Treatment of CM-prone animals with verapamil prevented any changes in DMIPP, FDG, or 201Tl uptake. DMIPP seems to be a more sensitive indicator of early cardiomyopathic changes as compared to 201Tl or FDG. The trial of DMIPP and SPECT in the diagnosis of human disease, as well as for monitoring the effects of drugs which may prevent it seems to be warranted.