Conceptual, methodological and computational issues concerning the compartmental modeling of a complex biological system: Postprandial inter-organ metabolism of dietary nitrogen in humans
2006
Juillet, Barbara | Saccomani, Maria Pia | Bos, Cécile | Gaudichon, Claire | Tomé, Daniel | Fouillet, Hélène | Laboratoire Charles Friedel ; Université Pierre et Marie Curie - Paris 6 (UPMC)-Ecole Nationale Supérieure de Chimie de Paris - Chimie ParisTech-PSL (ENSCP) ; Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Institut de Chimie - CNRS Chimie (INC-CNRS)-Centre National de la Recherche Scientifique (CNRS) | USC INRA / INA-PG : Ecologie des Populations et Communautés ; Institut National de la Recherche Agronomique (INRA)
International audience
显示更多 [+] 显示较少 [-]英语. A multi-compartmental model has been developed to describe dietary nitrogen (N) postprandial distribution and metabolism in humans. This paper details the entire process of model development, including the successive steps of its construction, parameter estimation and validation. The model was built using experimental data on dietary N kinetics in certain accessible pools of the intestine, blood and urine in healthy adults fed a [ 15 N]-labeled protein meal. A 13-compartment, 21-parameter model was selected from candidate models of increasing order as being the minimum structure able to properly fit experimental data for all sampled compartments. Problems of theoretical identifiability and numerical identification of the model both constituted mathematical challenges that were difficult to solve because of the large number of unknown parameters and the few experimental data available. For this reason, new robust and reliable methods were applied, which enabled (i) a check that all model parameters could theoretically uniquely be determined and (ii) an estimation of their numerical values with satisfactory precision from the experimental data. Finally, model validation was completed by first verifying its a posteriori identifiability and then carrying out external validation.
显示更多 [+] 显示较少 [-]