| Abstract: | Five individual ninhydrin positive fractions were found in the blood serum of rats in the control group with the help of high voltage electrophoresis in combination with preparative high voltage electrophoresis and paper chromatography. An analogous analysis of the blood serum of the test animals treated with 50 mg/kg of chlortetracycline for 12 days revealed 1 new fraction in the weak basic region. After the use of chlortetracycline for 18 days 2 new fractions in the strong acid region, 1 new fraction at the level of the electrophoretic mobility of asparaginic acid and 2 fractions in the region between neutral and basic amino acids were found. Analysis of the above fractions showed that the blood sera of the control and test rats contained in addition to the free amino acids peptides consisting of 3 to 9 amino acid residues. Some peptides isolated from the sera of the test animals contained amino acids, such as ornithine and citrulline which are not usually contained in proteins. |
