*4.8. Determination of p-Glycoprotein and Mrp 2*/*3*

Crude membrane from liver was prepared according to the method of Aleksunes et al. [30]. Each gram of liver was homogenized with 4 mL of sucrose-Tris buffer (0.25 M sucrose, 10 mM Tris-HCl, pH 7.4) containing 50 g/mL of aprotinin. The homogenate was then centrifuged at 100,000× *g* for 60 min at 4 ◦C. The resulting pellet was resuspended in sucrose-Tris buffer and was used for determinations of *p*-glycoprotein and Mrp2/3 by Western blot.
