PT - JOURNAL ARTICLE AU - Tracey K. Murray AU - Katherine Whalley AU - Christine S. Robinson AU - Mark A. Ward AU - Caroline A. Hicks AU - David Lodge AU - Jim L. Vandergriff AU - Polly Baumbarger AU - Edward Siuda AU - Mary Gates AU - Ann M. Ogden AU - Phil Skolnick AU - Dennis M. Zimmerman AU - Eric S. Nisenbaum AU - David Bleakman AU - Michael J. O'Neill TI - LY503430, a Novel α-Amino-3-hydroxy-5-methylisoxazole-4-propionic Acid Receptor Potentiator with Functional, Neuroprotective and Neurotrophic Effects in Rodent Models of Parkinson's Disease AID - 10.1124/jpet.103.049445 DP - 2003 Aug 01 TA - Journal of Pharmacology and Experimental Therapeutics PG - 752--762 VI - 306 IP - 2 4099 - http://jpet.aspetjournals.org/content/306/2/752.short 4100 - http://jpet.aspetjournals.org/content/306/2/752.full SO - J Pharmacol Exp Ther2003 Aug 01; 306 AB - Glutamate is the major excitatory transmitter in the brain. Recent developments in the molecular biology and pharmacology of the α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) subtype of glutamate receptors have led to the discovery of selective, potent, and systemically active AMPA receptor potentiators. These molecules enhance synaptic transmission and play important roles in plasticity and cognitive processes. In the present study, we first characterized a novel AMPA receptor potentiator, (R)-4′-[1-fluoro-1-methyl-2-(propane-2-sulfonylamino)-ethyl]-biphenyl-4-carboxylic acid methylamide (LY503430), on recombinant human GLUA1–4 and native preparations in vitro and then evaluated the potential neuroprotective effects of the molecule in rodent models of Parkinson's disease. Results indicated that submicromolar concentrations of LY503430 selectively enhanced glutamate-induced calcium influx into human embryonic kidney 293 cells transfected with human GLUA1, GLUA2, GLUA3, or GLUA4 AMPA receptors. The molecule also potentiated AMPA-mediated responses in native cortical, hippocampal, and substantia nigra neurons. We also report here that LY503430 provided dose-dependent functional and histological protection in animal models of Parkinson's disease. The neurotoxicity after unilateral infusion of 6-hydroxydopamine into either the substantia nigra or the striatum of rats and that after systemic 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine in mice were reduced. Interestingly, LY503430 also had neurotrophic actions on functional and histological outcomes when treatment was delayed until well after (6 or 14 days) the lesion was established. LY503430 also produced some increase in brain-derived neurotrophic factor in the substantia nigra and a dose-dependent increases in growth associated protein-43 (GAP-43) expression in the striatum. Therefore, we propose that AMPA receptor potentiators offer the potential of a new disease modifying therapy for Parkinson's disease. The American Society for Pharmacology and Experimental Therapeutics