SLC22A7 is a sodium-independent multispecific organic anion transporter, expressed in liver and kidney, that also has acetylsalicylate (ASA-) and salicylate (ST) as substrate (Sekine et al, 1998; Sun et al, 2001). Uptake of ASA- by rat hepatocytes is slow and caused by an apparently linear process (Iwamoto et al, 1984).
The human gene SLC22A7 encodes organic anion transporter 2 (OAT2) and is highly expressed in the liver and kidney (Sun W et al, 2001; Kobayashi Y et al, 2005). The human gene SLC22A11 encodes organic anion transporter 4 (OAT4) which is highly expressed in the placenta and kidney (Cha SH et al, 2000; Ekaratanawong S et al, 2004). Both of these transporters mediate the influx of sulfate conjugates with antiport of dicarboxylic acid. OAT2 is classified as both a transporter of organic anions and sulphate conjugates.
The human gene SLC22A6 encodes organic anion transporter1 (OAT1). It was originally characterized in mouse as Novel Kidney Transcript (NKT). OAT1 is located on the basolateral membrane of the proximal tubule in human kidney as well as in the brain (Reid G et al, 1998; Lu R et al, 1999; Hosoyamada M et al, 1999). The human gene SLC22A7 encodes organic anion transporter 2 (OAT2) and is highly expressed in the liver and kidney (Sun W et al, 2001; Kobayashi Y et al, 2005). The human gene SLC22A8 encodes organic anion transporter 3 (OAT3) which is expressed mainly in the brain and kidney (Race JE et al, 1999; Bakhiya A et al, 2003). OAT1-3 transport organic anions such as p-aminohippurate and drugs such as cimetidine and acyclovir. This transport is is coupled with an efflux of one molecule of endogenous dicarboxylic acid such as alpha-ketoglutarate (2-oxoglutarate). OAT2 is classified as both a transporter of organic anions and sulphate conjugates.