(13)C-Leucine-tracer-technique for in-vivo measurement of amino acids' metabolism by human colon carcinomas.

Own investigations on in-vivo tumor metabolism of the malignant human colon tumor showed a significant uptake of branched chain amino acids by the tumor itself. To study the quantitative tumor protein metabolism ("compartment "tumor") the(13)C-leucine-tracer-technique was modified.Beside the common(13)C-leucine-breath-test we measured also the AV-differences of(13)C-leucine,(13)C-ketoisocaproate and(13)CO2. The "Tumorblood flow" was measured by "venous-outflow-technique" as well as the tumor mass.In this way it is possible to get quantitative results in substrate exchange of branched chain amino acids in malignant human colon tumors.