FIG. 1.
The second part of the K&N model, describing Cd kinetics from systemic uptake to excretion. The amount of Cd in total plasma (y2) is calculated as C20 × (Plasma other + Plasma metallothionein). Abbreviations: I, amount daily systemic uptake; y1, amount in whole blood; y2, amount in total plasma; y3, amount in kidney; y4, amount in 24-h urine; C7, fraction from daily systemic uptake to plasma metallothionein; C9, fraction from other plasma to other tissue; C10, transfer rate from other tissue to other plasma; C11, fraction from other plasma to fecal excretion; C12, fraction from other plasma to liver; C13, transfer rate from liver to other plasma; C14, transfer rate from liver to plasma metallothionein; C15, excretion rate from liver to feces; C16, transfer rate from red blood cells to plasma metallothionein; C17, tubular reabsorptive capacity; C18, transfer rate from kidney to other plasma; C19, excretion rate of Cd accumulated in kidney to 24-h urine; CX, fraction from other plasma to red blood cells; C20, fraction of Cd in the plasma compartments contributing to whole blood.