PRELIMINARY STUDIES OF ~(99m)T_c LABELED FATTY ACID ANALOGS FOR MYOCARDIAL IMAGING

Radio iodine labelled fatty acid analogs are potential myocardial imaging agents for SPECT. In this paper are reported three new99mTc labelled fatty acid analogs. 99mTc-BAT-TDA, 99mTc-BAT-PDA and 99mTc-BAT-HxDA. Ligand exchange reaction with99mTc stannous glucoheptonate in 50% aqueous ethanol is used for labelling. With a yield of 87%, 70%, 49% respectively. 99mTc-fatty acid is purified by extraction into chloroform and the purity as determined by reverse phase HPLC is 98%. In order to determine the structure of Tc-BAT-fatty acid, 99Tc-BAT-PDA is synthesized with 99Tc ammonium pertechnetate in 50% citric acid buffer (pH=6) /ethanol using stannous chloride as the reducing agent. 99Tc-BAT-PDA displays the expected Tc = O UV absorption at 420nm and strong peak at 900cm-1 in the FTIR spectrum.Biodistribution studies of three 99mTc-fatty acid analogs are conducted in rats using 125I-ω- (p-iodophenyl) -penta-decanoic acid (IPPDA) as internal standard. The initial heart uptake of them is significantly lower than that of 125I-IPPDA.