Dicarboxylate anions, transporter systems

H+ cotransporters of low specificity.500 A Cl- / oxalate transporter is one of several ion exchange proteins in the kidney.501 Transport systems for ADP, phosphate, dicarboxylates, and other anions are very active in mitochondrial membranes (Chapter 18). 

Carrier-mediated membrane transport proteins on the RPE selectively transport nutrients, metabolites, and xenobiotics between the choriocapillaris and the cells of the distal retina, and include amino acid [33 35], peptide [36], dicarboxylate, glucose [37], monocarboxylic acid [38,39], nucleoside[40], and organic anion and organic cation [41] transporters. Membrane barriers such as the efflux pumps, including multidrug resistance protein (P-gp), and multidrug resistance-associated protein (MRP) pumps have also been identified on the RPE. Exploitation of these transport systems may be the key to circumventing the outer BRB. 

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