[Study on technetium-99m in radiopharmaceuticals].

The technetium field involving a new element of which chemistry has not been honed in the research during the century is particularly challenging, it is exciting and satisfying to see the successful development of a radiopharmaceutical agent which gives the clinical doctor new tools with which to assess function and in vivo biochemistry in nuclear medicine. The clinical application of technetium in nuclear medicine will parallel with the development of technetium chemistry in organic-, analytical-, medical- and biochemistry, and it is likely that useful new Tc-99m radiopharmaceuticals will rapidly make world-wide progress in the future years. The design and synthetic modifications of ligand structure in organic chemistry will impart new biological properties to the technetium complexes. A structure characterization Tc-99m labelled radiopharmaceuticals is highly desirable in analytical chemistry. We take much interest in the structural characterization of Tc-99m complexes stems to establish a structure/in vivo activity relationship in medical chemistry. The current clinical trend is to use Tc-99 radiopharmaceuticals with Tc-99m "carrier-added" experiments for studies of chemical structure and biochemical mechanism of action. Technical difficulties in the various labeling approaches to these bifunctional chelating agents (BCA) which seem promising are often encountered during the ached procedures. High priority is given to development of Tc-99 m radiopharmaceuticals for studies of substrate utilization and localization of specific biological recognition sites. New accomplishments in technetium radiopharmaceutical are likely to be reported in the near future.