DISTRIBUTION OF RADIOACTIVITY OF INTRAPERITONEALLY ADMINISTERED C-14 LEUCINE AND C-14 ALANINE IN TISSUES OF SUCKLING LAMBS

C-14-labelled leucine and alanine were administered intraperitoneally to suckling male lambs aged 30. The distribution of radioactivity was investigated in the liver, heart, quadriceps femoris muscle, subcutane ous adipose tissue, skin and expired air. Most of the radioactivity (p er 1 g of dry tissue) was found in proteins of liver, followed by prot eins of the heart, skin, muscle and adipose tissue. The radioactivity found in lipids and glycogen was much lower, with the exception of hig h radioactivity of leucine-derived lipids of the adipose tissue. Incor poration of alanine into proteins was lower than that of leucine. On t he other hand, more alanine was oxidized to CO2 than leucine.