In Vitro | In vitro activity: GSK189254A (also known as GSK189254) is a novel histamine H(3) receptor antagonist with high affinity for human (pK(i) = 9.59 -9.90) and rat (pK(i) = 8.51-9.17) H(3) receptors. It has the potential for the treatment of narcolepsy. GSK189254 is>10,000-fold selective for human H(3) receptors versus other targets tested, and it exhibited potent functional antagonism (pA(2) = 9.06 versus agonist-induced changes in cAMP) and inverse agonism [pIC(50) = 8.20 versus basal guanosine 5'-O-(3-[(35)S]thio)triphosphate binding] at the human recombinant H(3) receptor. In vitro autoradiography demonstrated specific [(3)H]GSK189254 binding in rat and human brain areas, including cortex and hippocampus. GSK189254 may have therapeutic potential for the symptomatic treatment of dementia in Alzheimer's disease and other cognitive disorders.
Kinase Assay: GSK189254A (also known as GSK189254) is a novel histamine H(3) receptor antagonist with high affinity for human (pK(i) = 9.59 -9.90) and rat (pK(i) = 8.51-9.17) H(3) receptors. GSK189254 has high affinity for both recombinant H3 receptors expressed in HEK-293-MSR-II cells and native H3 receptors expressed in the cerebral cortex of several species. GSK189254 generally exhibits higher affinity for human and pig H3 receptors compared with rat,mouse, and dog H3 receptors. [3H]GSK189254 binds in rat and human brain areas, including cortex and hippocampus. GSK189254 may have therapeutic potential for the symptomatic treatment of dementia in Alzheimer’s disease and other cognitive disorders.
Cell Assay: |
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In Vivo | After oral administration, GSK189254 inhibited cortical ex vivo R-(-)-alpha-methyl[imidazole-2,5(n)-(3)H]histamine dihydrochloride ([(3)H]R-alpha-methylhistamine) binding (ED(50) = 0.17 mg/kg) and increased c-Fos immunoreactivity in prefrontal and somatosensory cortex (3 mg/kg). GSK189254 (0.3-3 mg/kg p.o.) increases the release of acetylcholine, noradrenaline, and dopamine in the anterior cingulate cortex and acetylcholine in the dorsal hippocampus. GSK189254 significantly improves performance of rats in diverse cognition paradigms, including passive avoidance, water maze, object recognition, and attentional set shift. In Ox+/+ and Ox–/– mice, acute administration of GSK189254 increases W and decreases slow wave and paradoxical sleep to a similar degree to modafinil, while it reduces narcoleptic episodes in Ox–/– mice |
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