Rush DK

References (4)

Title : Pharmacological activity and safety profile of P10358, a novel, orally active acetylcholinesterase inhibitor for Alzheimer's disease - Smith_1997_J.Pharmacol.Exp.Ther_280_710
Author(s) : Smith CP , Bores GM , Petko W , Li M , Selk DE , Rush DK , Camacho F , Winslow JT , Fishkin R , Cunningham DM , Brooks KM , Roehr J , Hartman HB , Davis L , Vargas HM
Ref : Journal of Pharmacology & Experimental Therapeutics , 280 :710 , 1997
Abstract : 1-[(3-Fluoro-4-pyridinyl)amino]-3-methyl-1(H)-indol-5-yl methyl carbamate (P10358) is a potent, reversible acetylcholinesterase inhibitor that produces central cholinergic stimulation after oral and parental administration in rats and mice. P10358 is a 2.5 times more potent acetylcholinesterase inhibitor than THA in vitro (IC50 = 0.10 +/- 0.02 microM vs. IC50 = 0.25 +/- 0.03 microM). It also inhibits butyrylcholinesterase activity as potently as THA (IC50 = 0.08 +/- 0.05 microM vs. IC50 = 0.07 +/- 0.01 microM). Ex vivo, P10358 (0.2 - 20 mg/kg, p.o.) produced dose-dependent inhibition of brain acetylcholinesterase activity. At 10 and 20 mg/ kg, it produced profound and long-lasting hypothermia in mice. P10358 enhanced performance in rats in a step-down passive avoidance task (0.62 and 1.25 mg/kg) and in a social recognition paradigm (0.32, 0.64 and 1.25 mg/kg) in mice. It reversed scopolamine-induced deficits in the Morris Water maze in rats (1.25 and 2.5 mg/kg) and a higher dose elevated striatal homovanillic acid levels. These behavioral and biochemical effects are consistent with central cholinergic stimulation. Hemodynamic studies in the rat demonstrated a 16-fold separation between behaviorally active doses (1.25 mg/kg) and those that elevated arterial pressure (20 mg/kg). Lethality in rats occurred at an oral dose of 80 mg/kg, but not at lower doses. Chemically, P10358 is an N-aminoindole and may not have the hepatotoxic liability associated with aminoacridine structure of tacrine. P10358 had weak affinity (>10 microM) at a variety of aminergic and peptidergic receptors and uptake carriers. These properties suggest that P10358 may be a safe and promising symptomatic treatment for Alzheimer's disease.
ESTHER : Smith_1997_J.Pharmacol.Exp.Ther_280_710
PubMedSearch : Smith_1997_J.Pharmacol.Exp.Ther_280_710
PubMedID: 9023283

Title : Pharmacological evaluation of novel Alzheimer's disease therapeutics: acetylcholinesterase inhibitors related to galanthamine - Bores_1996_J.Pharmacol.Exp.Ther_277_728
Author(s) : Bores GM , Huger FP , Petko W , Mutlib AE , Camacho F , Rush DK , Selk DE , Wolf V , Kosley RW, Jr. , Davis L , Vargas HM
Ref : Journal of Pharmacology & Experimental Therapeutics , 277 :728 , 1996
Abstract : Acetylcholinesterase (AChE) inhibitors from several chemical classes have been tested for the symptomatic treatment of Alzheimer's disease; however, the therapeutic success of these compounds has been limited. Recently, another AChE inhibitor, galanthamine hydrobromide (GAL), has shown increased clinical efficacy and safety. Using biochemical, behavioral and pharmacokinetic analyses, this report compares GAL with two of its analogs, 6-O-acetyl-6-O-demethylgalanthamine hydrochloride (P11012) and 6-O-demethyl-6-O[(adamantan-1-yl)-carbonyl]galanthamine hydrochloride (P11149), for their therapeutic potential. P11012 and P11149 were found to be potent, competitive and selective inhibitors of AChE, demonstrating central cholinergic activity, behavioral efficacy and safety. P11012 and P11149, though pharmacokinetic analyses, were shown to act as pro-drugs, yielding significant levels of 6-O-demethylgalanthamine. In vitro, 6-O-demethylgalanthamine was 10- to 20-fold more potent than GAL as an inhibitor of AChE, and it demonstrated greater selectivity for inhibition of AChE vs. butyrylcholinesterase. Like GAL, both P11012 and P11149 showed central cholinergic activity biochemically, by significantly inhibiting rat brain AChE; physiologically, by causing hypothermia; and behaviorally, by attenuating scopolamine-induced deficits in passive avoidance. In addition, GAL, P11012 and P11149 enhanced step-down passive avoidance, another measure of behavioral efficacy. By comparing efficacious doses with primary overt effects, P11012 and P11149 had better oral therapeutic indices than GAL. Oral pharmacokinetic analyses of GAL, P11012 and P11149 revealed differences. Although P11012 and P11149 exhibited similar area under the curve values, 191149 had slower, lower and more sustained concentration maximum levels. P11012 and GAL rapidly reached their concentration maximums, but GAL, in brain had the highest area under the curve and concentration maximum. Because of its composite profile, including duration of action, oral therapeutic index and pharmacokinetics, P11149 is considered the better therapeutic candidate for the treatment of Alzheimer's disease.
ESTHER : Bores_1996_J.Pharmacol.Exp.Ther_277_728
PubMedSearch : Bores_1996_J.Pharmacol.Exp.Ther_277_728
PubMedID: 8627552

Title : Velnacrine maleate improves delayed matching performance by aged monkeys - Jackson_1995_Psychopharmacology_119_391
Author(s) : Jackson WJ , Buccafusco JJ , Terry AV, Jr. , Turk DJ , Rush DK
Ref : Psychopharmacology , 119 :391 , 1995
Abstract : Velnacrine maleate is a novel, orally active acetylcholinesterase inhibitor of the acridine class with a longer duration of action than physostigmine. Velnacrine has shown efficacy in the treatment of Alzheimer's disease and in improving both normal and experimentally impaired mnemonic function in animals and humans. To characterize this action further, the present study evaluated velnacrine for its ability to ameliorate the decline in short-term memory associated with aging in non-human primates at two time points after velnacrine administration: (1) 30 min and (2) 24 h. Initially, doses of 1, 2, 4, and 6 mg/kg, PO (free base corrected) were administered once to each of six aged (25-40 years), memory-impaired macaques that had been trained to perform a delayed matching-to-sample (DMTS) paradigm. The dose associated with the greatest improvement in session performance was administered three more times to the same individual. Four of the six monkeys showed improved DMTS performance during the repeated best dose phase (phase 2). Almost all of the improvement occurred during long-delay trials. Compared to placebo trials, velnacrine induced a significant improvement of long delay DMTS (58.0-66.7%, 13.4% of the placebo value). Long delay DMTS remained significantly improved during the test session conducted 24 h following velnacrine administration. Pharmacokinetic analysis following administration of 4 or 6 mg/kg velnacrine to three aged monkeys revealed peak plasma concentrations ranging from 27 to 166 ng/ml, 30-60 min after dosing. Six hours after dosing velnacrine plasma levels decreased to 5.1-11.8 ng/ml; and 24 h after dosing velnacrine plasma levels were less than the limit of quantitation (5 ng/ml)
ESTHER : Jackson_1995_Psychopharmacology_119_391
PubMedSearch : Jackson_1995_Psychopharmacology_119_391
PubMedID: 7480518

Title : Synthesis and evaluation of 5-amino-5,6,7,8-tetrahydroquinolinones as potential agents for the treatment of Alzheimer's disease - Fink_1995_J.Med.Chem_38_3645
Author(s) : Fink DM , Bores GM , Effland RC , Huger FP , Kurys BE , Rush DK , Selk DE
Ref : Journal of Medicinal Chemistry , 38 :3645 , 1995
Abstract : A series of 5-amino-5,6,7,8-tetrahydroquinolinones was designed and synthesized as acetylcholinesterase inhibitors. The compounds are related to hyperzine A, a naturally occurring cholinesterase inhibitor. They inhibit acetylcholinesterase in vitro, and many are active in vivo in reversing a scopolamine-induced impairment of 24 h memory in a passive avoidance paradigm. Although these compounds were designed as partial structures of huperzine A, it is unlikely that they bind to the enzyme in a similar fashion, since they lack the unsaturated three-carbon bridge of huperzine A and both the quinolinone nitrogen and the amino group must be substituted in order to obtain good enzyme affinity.
ESTHER : Fink_1995_J.Med.Chem_38_3645
PubMedSearch : Fink_1995_J.Med.Chem_38_3645
PubMedID: 7658452