Autoradiographic Studies on the Distribution of Radioisotope I. Distribution of ¹⁴C-Amino Acid

Abstract

The distribution of ¹⁴C-amino acid (¹⁴C-glycine, ¹⁴C-isoleucine, ¹⁴C-valine, ¹⁴C-aspartic acid and ¹⁴C-glutamic acid) has been studied by means of autoradiographic method with whole animal slice section of 10 days old baby mouse.
The distribution pattern of these amino acids seemed to be divided into two types. One was in the case, ¹⁴C-isoleucine, ¹⁴C-valine and ¹⁴C-glycine being injected, their radioactivity in all tissues reached the high level at 7 hrs after administration and continued over 96 hrs. The other was in the case, ¹⁴C-aspartic acid and ¹⁴C-glutamic acid being injected, the intense activity was noted at 3 and 24 hrs., respectively, but it gradually disappeared and scarcely detected in tissues at 96 hrs. Besides, it was of interest that in the early period after injection ¹⁴C-aspartic acid and ¹⁴C-glutamic acid, specific and dense localization of ¹⁴C occurred in the skeleton.