The resin-strip made of Amberlite IRA 400 was used for the elimination of iron ion added to serum to determine unsaturated iron-binding capacity (UIBC) . More than 95% of iron ion in the serum was eliminated within one hour with two resin-strips of 0.4 gram wet weight. No significant effect of heparin, iron ion concentration, and temperature to UIBC values was observed. UIBC values obtained by the resin-strip were in good agreement with those by magnesium carbonate powder. The resin-strip is picked out before counting sample and the procedure is largely simplified; centrifugation, pipetting for supernatant counting, and addition of buffer solution are not needed.
Removal of mercury, bound to sulfhydryl groups of hemoglobin, by various Chelating agents containing sulfhydryl group, was investigated by the use of equilibrium dialysis. Chelating agents employed were cysteine, penicillamine, glutathione, mercaptoacetic acid and their related compounds. Both inorganic and organic mercury compounds were most effectively removed at physiological pH. As to ethylmercuric chloride, linear correlation was found between the percentage of removal and the dissociation constants of sulf hydryl group of the chelating agents. The effect of the sulfur-oxygen coordinating chelating agent was about 20% greater than that of the sulfur-nitrogen coordinating chelating agent. On the other hand, the removal of mercuric chloride from hemoglobin was independent of the acid dissociation constants of the chelating agents. The effect of the isosteric substitution of the coordinating atom was seen by the fact that the ability of the removal of mercury decreases in the order selenocysteamine > cysteamine >> ethanolamine for ethylmercuric chloride, and cysteamine > selenocysteamine >> ethanolamine for mercuric chloride. A ternary complex, hemoglobin-mercury-cysteine complex, which is considered to be an important intermediate in the removal of mercury was found by the gel-filtration technique.
5-iodocytosine-131I was synthesized by the exchange reaction of 5-IC with Na131I. Specific activity of synthesized 5-131IC was 450 μCi/mg (0. 34 mCi/ml) . The autoradiolysis was 7% in 30 days. Studies of distribution of 5-131IC in mice and scintiphotography indicated that the intraperitoneally injected 5-131IC was incorporated into the stomach, lung and tumor, and excreted to the kidney. The whole body macroautoradiography showed the incorporation of 5-131IC into the implanted tumor in mice (6 hr after intraperitoneal injection) .