Pharmacology study of the neutral myocardial imaging agent technetium-99m-N(NOEt)2.

OBJECTIVE The biological properties of a new neutral myocardial imaging agent 99mTcN(NOEt)2 were evaluated. METHODS Blood clearance in rabbits, biodistribution in rats, and initial myocardial imaging in dogs were performed. RESULTS Radiochemical purity of 99mTcN(NOEt)2 was more than 90% and stable for 6 h at room temperature. Blood disappearance was analyzed with a biexponential model and T1/2(alpha) = 2.53 min, T1/2(beta) = 330 min and CI = 378 ml/h were obtained. Biodistribution studies demonstrated that 99mTcN(NOEt)2 localized selectively in the rat myocardium. Cardiac uptakes were 4.69, 4.20, 3.95 and 3.43% ID/g at 5, 30, 60 and 90 min postinjection, respectively. The mean heart-to-lung activity ratios were 1.69, 2.40 and 2.55 at 10 min, 30 min and 60 min postinjection, respectively. CONCLUSION Technetium-99m-N(NOEt)2 exhibited favorable stability and biological properties. Further study in humans is required.