Fig. 2.

Western blot analyses of the purity of the BBMV_CTX and BBMV_PCT. A: analysis of contaminating organelle and basolateral membranes. Samples containing 20 μg of crude homogenates of rat renal cortex and BBMV_CTX were separated by SDS-PAGE and probed with antibodies that are specific for the apical (BBM) Na⁺/H⁺ exchanger-3 (NHE3), the basolateral (BLM) glucose transporter (GLUT2), the mitochondrial (MITO) succinate dehydrogenase (SDH), and the endoplasmic reticulum (ER) marker calnexin (CNX). B: analysis of contaminating apical membranes. Samples containing 20 μg of renal cortex and BBMV_CTX or isolated BBMV_PCT were probed for proteins that, within the cortex, are expressed only in the proximal tubule (PT), Na⁺/H⁺ exchanger regulatory factor-1 (NHERF1); the thick ascending limb (TAL), Na⁺K⁺2Cl⁻-cotransporter-2 (NKCC2); the distal tubule (DT), thiazide-sensitive Na⁺Cl⁻ co-transporter (TSC); and the collecting duct (CD), aquaporin-2 (AQP2). For each protein, the spacing denotes where a lane was deleted from the original figure of a single gel.