Sensitivity Analysis Techniques Applied to a Revised Model of Molybdenum Biokinetics

A revised model of molybdenum biokinetics in humans was recently developed on the basis of experimental data gathered in specific investigations conducted with stable tracers. The model can be used for radiation protection purposes, and it is also a suitable working tool for designing new investigation studies, aimed at further model improvements. According to the latter goal, a sensitivity analysis was performed in order to determine the most significant model parameters in relation to output measurements performed in studies of molybdenum metabolism.A typical sensitivity analysis approach was adopted, considering the effects in variation of model parameters on the lime courses of mode 1 outputs, as urinary excretion and blood clearance. A recent new sensitivity technique was considered too, based on the calculation of the so-called generalised sensitivity functions. It combines the sensitivities of the model output with respect to model parameters (as in the typical sensitivity analysis method), with the sensitivities of parameter estimates with respect to changes in model outputs.The results obtained in these analyses suggest that data collected in the first 7 hours are critical for the definition of the process of blood clearance and of the related parameters, whereas reliable information at later times is required for a proper characterization of urinary excretion.