Model Analysis of Oxygen Isotope Fractionation in Humans Due to Disturbances of Pulmonary Gas Exchange
The lighter isotopic oxygen molecule 1602 passes through the human oxygen transport system with an approximately 0.8% higher rate than its heavier isotopic species 160180, leading to an overall fractionation effect which has recently been quantified (Schuster and Pflug, 1989). This effect has been measured in healthy persons at rest and during ergometer work (Schuster et al., 1994), situations of hyper-and hypoventilation have been studied (Heller et al., 1993), and patients suffering from anemia (Heller et al., 1994) or lung fibrosis have been investigated (Heller et al., this volume). All these situations affected the overall fractionation effect due to changes of processes of the oxygen transport system. Therefore it is supposed that this parameter and its change contains characteristic information with respect to the pattern of oxygen transport pathways and its variations. To understand the sources of the fractionation effects and their nature, model investigations are necessary. This study models changes of pulmonary gas exchange disturbances with respect to their influence on the overall fractionation effect so as to interpret experimental data.
KeywordsInterstitial Lung Disease Isotope Fractionation Diffusion Resistance Fractionation Power Fractionation Effect
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