Kunio Kurata

Chemical and biological studies on 99mTc-DMS—II: Effect of Sn(II) on the formation of various Tc-DMS complexes

Various Tc-dimercaptosuccinate (Tc-DMS) complexes were prepared using both 99mTc and carrier 99Tc. A yellow complex (Complex I) was obtained at low concentration of Sn(II), and a purple complex (Complex II) with a large excess amount of Sn(II). Potentiometric titration of Sn(II)-DMS indicates the formation of a 1:1 complex alone, which can be utilized as a reducing agent of TcO4−. The absorption spectra that there is little possibility of a mixed metal complex of Tc-Sn-DMS. Potentiometric and radiometric titrations were used for the determination of the technetium valence state. It was found that the pertechnetate is reduced to the IV state, which is due to the formation of Complex I. The formation of Complex II is increased as the amount of Sn(II) as well as the molar ratio of Sn(II)/Sn(IV) is increased or the TcO4- concentration decreased. Maximum Complex II formation was observed at the 99mTcO4- only concentration level. Complex II showed the highest kidney uptake, and it is suggested that the Complex II might be a Tc(III)-DMS.

Immunological properties of β-fructofuranosidase from ripening tomato fruit

Abstract The amount of tomato fruit β-fructofuranosidase extractable from the cell walls during ripening parallelled the changes in activity of the enzyme. Using the techniques of radioimmunoassay, double immunodiffusion analysis and immunotitration, no differences in immunological properties of β-fructofuranosidase between the various stages of fruit ripening were detected.

Chemical and biological studies on 99mTc-DMS—I: Formation of complexes by four different methods

Abstract Various kinds of 99m Tc-dimercaptosuccinate ( 99m Tc-DMS) complexes were prepared by electrochemical, electrolysis, SnCl 2 and NaBH 4 -HCl methods. In all methods, less than 0.1% of free 99m TcO 4 − was detected in the original preparation. The biological distribution and chromatographic behavior of the product depended greatly upon the method of preparation. Electrophoretic and paperchromatographic patterns of 99m Tc-DMS prepared by these four different methods were separated into two peaks. One peak was detected at nearly the same spot as free DMS while the other peak remained at the origin. One of the 99m Tc-DMS complexes which remained at the origin during the separation procedure was accumulated in the kidney. The highest kidney uptake was observed by the sample prepared by SnCl 2 method at pH=2, at 3 hr after injection into mice. The 99m Tc-DMS complex prepared by the electrochemical method at pH=10 was accumulated significantly by bone, which might be useful for bone scanning.

Selective degradation of altered tomato β-fructofuranosidase molecules by neutral protease

Abstract Evidence is presented for the selective breakdown of altered tomato β-fructofuranosidase molecules by a neutral protease from Bacillus subtilis .