Einfluß des natürlichen Isotopengehaltes von Nährstoffen auf den Untergrund bei13C-Atemtests

Abstract

The long-term variation of the mean delta 13C-value of breath-CO2 of Europeans (base value -26%) was +/- 1% over a period of several months. However, the ingestion of products from corn, a C4-plant, caused remarkably higher shifts. In a fasted state and during rest a stability of the base value of +/- 0.3% could be attained for several hours. Longer fasting periods imply a shift of the CO2-delta-value due to the metabolism of body products. - By a change of the main energy source to corn products the delta 13C-base line could be shifted to -18% within one day. After this shift even the metabolism of products from C3-plants could be investigated. The degradation curve and the integral degradation of fats were largely dependent on the method of application, and the base value largely interfered with the results. The period of maximum disintegration for a naturally and uniformly labelled fat was different from that of an artificially labelled trilinoleate. The results shall be used for the adjustment and the correction of the base line in 13C-breath tests, especially with patients under parenteral nutrition.

Special Issue dedicated to Professor Hanns-Ludwig Schmidt on the occasion of his 85th birthday

“…H.-L. Schmidt and his group applied naturally 13 C enriched food or macronutrients based on C 4 plants not only for breath tests [31], but also to follow digestion, absorption and oxidation of macronutrients in vivo in human subjects and animals [32,33]. Later on, work dealing with amino acid metabolism based on natural tracers, and on 13 C and 15 N labelled substances became possible [34,35] as a result of methodological developments (e.g.…”

Estimation of Arachidonic Acid Synthesis in Full Term Neonates Using Natural Variation of 13C Content

“…In regions such as Europe, where most foods consumed are based on C 3 plants with a relatively low l3C content (6), a less expensive alternative is the feeding of diets based on C 4 plants, which are naturally enriched in l3C because they fix carbon dioxide by the C 4 pathway (7). This approach has already been used in l3C breath tests (8,9) to study fat and carbohydrate metabolism in humans. The application of this concept to the evaluation of fatty acid metabolism requires the accurate measurement of small changes in the l3C content of individual fatty acid metabolites in plasma that do not exceed possible variations in natural abundance.…”