PURPOSE: Drug delivery to the brain is impeded by the blood-brain barrier (BBB). Here, we attempted to enhance the brain uptake of cationic dopamine by utilizing the large amino acid transporter 1 (LAT1) at the BBB by prodrug approach. METHODS: Three amino acid prodrugs of dopamine were synthesized and their prodrug properties were examined in vitro. Their LAT1-binding and BBB-permeation were studied using the in situ rat brain perfusion technique. The brain uptake after intravenous administration and the dopamine-releasing ability in the rat striatum after intraperitoneal administration were also determined for the most promising prodrug. RESULTS: All prodrugs underwent adequate cleavage in rat tissue homogenates. The prodrug with phenylalanine derivative as the promoiety had both higher affinity for LAT1 and better brain uptake properties than those with an alkyl amino acid - mimicking promoiety. The phenylalanine prodrug was taken up into the brain after intravenous injection but after intraperitoneal injection the prodrug did not elevate striatal dopamine concentrations above those achieved by corresponding L-dopa treatment. CONCLUSIONS: These results indicate that attachment of phenylalanine to a cationic drug via an amide bond from the meta-position of its aromatic ring could be highly applicable in prodrug design for LAT1-mediated CNS-delivery of not only anionic but also cationic polar drugs.
PURPOSE: Drug delivery to the brain is impeded by the blood-brain barrier (BBB). Here, we attempted to enhance the brain uptake of cationic dopamine by utilizing the large amino acid transporter 1 (LAT1) at the BBB by prodrug approach. METHODS: Three amino acid prodrugs of dopamine were synthesized and their prodrug properties were examined in vitro. Their LAT1-binding and BBB-permeation were studied using the in situ rat brain perfusion technique. The brain uptake after intravenous administration and the dopamine-releasing ability in the rat striatum after intraperitoneal administration were also determined for the most promising prodrug. RESULTS: All prodrugs underwent adequate cleavage in rat tissue homogenates. The prodrug with phenylalanine derivative as the promoiety had both higher affinity for LAT1 and better brain uptake properties than those with an alkyl amino acid - mimicking promoiety. The phenylalanine prodrug was taken up into the brain after intravenous injection but after intraperitoneal injection the prodrug did not elevate striatal dopamine concentrations above those achieved by corresponding L-dopa treatment. CONCLUSIONS: These results indicate that attachment of phenylalanine to a cationic drug via an amide bond from the meta-position of its aromatic ring could be highly applicable in prodrug design for LAT1-mediated CNS-delivery of not only anionic but also cationic polar drugs.
Authors: Mikko Gynther; Jarmo Ropponen; Krista Laine; Jukka Leppänen; Paula Haapakoski; Lauri Peura; Tomi Järvinen; Jarkko Rautio Journal: J Med Chem Date: 2009-05-28 Impact factor: 7.446
Authors: Marlyn D Laksitorini; Paul K Kiptoo; Ngoc H On; James A Thliveris; Donald W Miller; Teruna J Siahaan Journal: J Pharm Sci Date: 2015-01-12 Impact factor: 3.534
Authors: Evan Augustyn; Karissa Finke; Arik A Zur; Logan Hansen; Nathan Heeren; Huan-Chieh Chien; Lawrence Lin; Kathleen M Giacomini; Claire Colas; Avner Schlessinger; Allen A Thomas Journal: Bioorg Med Chem Lett Date: 2016-04-11 Impact factor: 2.823
Authors: Arik A Zur; Huan-Chieh Chien; Evan Augustyn; Andrew Flint; Nathan Heeren; Karissa Finke; Christopher Hernandez; Logan Hansen; Sydney Miller; Lawrence Lin; Kathleen M Giacomini; Claire Colas; Avner Schlessinger; Allen A Thomas Journal: Bioorg Med Chem Lett Date: 2016-09-03 Impact factor: 2.823