FIGURE 1.

Model of VA kinetics in the brain of neonatal rats dosed orally with [³H]ROH on postnatal day 4. Circles represent compartments; arrows represent their interconnectivities. Squares indicate compartments defined by the plasma-forcing function. Compartments 10 and 1 represent plasma CM-associated REs and RBP-bound ROH, respectively. Compartments 18 and 8 represent brain retinol derived from CMs and RBP, respectively. CM, chylomicron; L(I,J), fractional transfer coefficient, representing the fraction of dose transferred from compartment (J) to compartment (I); RBP, retinol-binding protein; RE, retinyl ester; ROH, retinol; VA, vitamin A.