Nuclear Medicine Program progress report for quarter ending June 30, 1989

In this report the development of a simple and inexpensive spectrophotometric technique to determine the specific activity of spallation-produced copper-67 (Cu-67) is described. The method is based upon the well-known strong absorption at 480 nm of the orange-colored copper (II) complexes with bis-thiosemicarbazone (TSC) ligands. We have used the Cu(II) complex of phenylglyoxal (PC-TSC) and determined a calibration curve in an acidic ethanol-acetate buffer which is linear up to a concentration of 40 ppM (40 {mu}gm/ml) with a lower limit of detection of about 0.4 ppM. Also in this report, the results it the synthesis and tissue distribution in fasted rats of a series of five analogues of 3.3-dimethyl-substituted terminal para-iodophenyl fatty acids to determine the effects of total chain length on myocardial uptake and retention properties are summarized. The C-11, C-12, C-13, C-14, C-15 (3,3-DMIPP) and C-19 analogues were evaluated. The C-15 analogue showed the highest heart uptake. The shorter C-11 {yields} C-14 and the C-19 chain lengths showed much lower heart uptake and heart:blood values. These studies clearly demonstrate that the position of dimethyl-branching and the total chain length are both important factors which affect myocardial uptake.