On Cytoplasmic Free Amino Acids Converted from Exogenous Lactate in Vitro Ehrlich Ascites Tumor Tissue in Mice

"The conversion of amino acids from L-Iactate-UCa was investigated in the normal liver. and cancer tissues which obtained from the tumor-bearing animals (Ehrlich ascites tumor). Tissue homogenates of tumors and normal liver were incubated for 10 minutes in the water bath at the constant temperature (38'C). The assay of amino acid was performed quantitatively and qualitatively by the method of thin layer chromatography. in which two dimensional ascending method was used. The amino acid spots on the chromatoplate were identified by means of Rf value and colour developed in the ninhydrin .spray. The density and radioactivity of each spot were measured simultaneously by use of the Radio Thin-Layer Chromatogram Scanner. The specific activity (cprn/uM) of each amino .acid was obtained from the result of activity (cpm/ gm wet tissue) divided by amount (uM/gm wet tissue). The conversion ratio of each converted amino acid(%) was calculated as the ratio of S. A. of converted amino acid (cpm/uM) and S. A. of lactate added (225XI0' cpm/uM). The data obtained. were summerized as follows; 1. The amino acids converted from the added Llactate- U-C" were alanine. serine. glycine. glutamic .acid and aspartic acid in the cancer tissues and also in the normal hepatic tissues. 2. The specific activity of the converted amino acids were alanine 2245. serine 2353. glycine 9755 (highest). glutamic acid 2703. and aspartic acid 1503 cpm/uM. respectively. in the cancer tissues. 3. The conversion ratio from the added L-IactateU- C" of each converted amino acid was alanine 1.00. serine 1. 05. glycine 4.34. glutamic acid 1.20 and aspartic acidO.67%. Total conversion ratio was 8.26% in the cancer tissues. 4. In the normal hepatic tissues. the specific activity of each converted amino acid was alanine 2702. serine 2900. glycine 3721. glutamic acid 9556. (highest) and aspartic acid 1561 cpm/uM. respectively. 5. The conversion ratio calculated from the S. A. of the converted amino acid and the S. A. of the added lactate was alanine 1. 20. serine 1. 29. glycine 1.65, glutamic acid 4.25. and aspartic acid 0.69%. respectively. Thus the total conversion ratio was 9.08% in the normal hepatic tissues. From the above results. it was concluded that the accumulated lactic acid in the cancer tissues was not only used for further metabolites in carbohydrate metabo ism. but also considerable fraction of it was converted into the various amino acids which were necessary in the cancer tissue proliferation