- Role of blood-brain barrier organic anion transporter 3 (OAT3) in the efflux of indoxyl sulfate, a uremic toxin: its involvement in neurotransmitter metabolite clearance from the brain. Ohtsuki, S., Asaba, H., Takanaga, H., Deguchi, T., Hosoya, K., Otagiri, M., Terasaki, T. J. Neurochem. (2002)