Abstract
Distribution of 75Se in whole blood, serum, and erythrocytes, after subcutaneous injection in the form of L-selenocystine and sodium selenite to rabbits was examined. During the first 4 hr after the injection of both selenium compounds, 75Se appeared in greater concentration in the serum than in erythrocytes but after 10 days, concentration in the serum decreased to roughly epual level as that in erythrocytes. Biological half life of 75Se, calculated from the result of successive measurement of radioactivity, 7 and 6 days in whole blood, and 6 and 3 days in serum, respectivly, for L-selenocystine and sodium selenite. Distibution of 75Se in whole blood, serum, and erythrocytes was examined with sampled from a rat 30 min after intravenous injection of sodium 75Se-selenite (in vivo), and with rat blood incubated with sodium 75Se-selenite at 37°for 30 min (in vitro). A higher radioactive concentration was found in erythrocytes in in vivo experiment than that in in vitro experiment. Results of dialysis of sera obtained in vivo and in vitro experiments suggestad that there was some difference between the two sera in the manner of affinity of seleninm to serum protein. Concerning the distribution in erythrocytes, most of selenium was detected in hemoglobin, especially in globin. Globin tagged with 75Se obtained by in vivo experiment was hydrolyzed and separated by two-dimentional paper chromatography. The autoradiogram of this paper indicated that the hydrolyzate contained at least 4 differnt componds bearing 75Se, two of these seemed to be methionine and cystine or cysteine.
