Protein expression of different renal ABC transporters. Total membrane fractions of rat kidney were isolated and expression of Abcb1/P-gp (a, b), Abcb11/Bsep (c), Abcc2/Mrp2 (d, e), and Abcc4/Mrp4 (f, g) was determined by Western blotting. Representative images (n = 4) show maximal Abcb1/P-gp protein expression 12 and 24 h after LPS+ (a), and coadministration with aminoguanidine reversed this induction (b). The protein expression of Abcb11/Bsep was up-regulated 12 h after LPS+ treatment, which was reversed by aminoguanidine (c). Maximal Abcc2/Mrp2 protein expression was seen 12 h after LPS+ (d) and aminoguanidine reversed this induction (e). Abcc4/Mrp4 protein expression was down-regulated during endotoxemia (f), which was intensified by aminoguanidine (g)