ABSTRACT
Previous research on histamine H(3) antagonists has led to the development of a pharmacophore model consisting of a central phenyl core flanked by two alkylamine groups. Recent investigation of the replacement of the central phenyl core with heteroaromatic fragments resulted in the preparation of novel 3,5-, 3,6- and 3,7-substituted indole and 3,5-substituted benzothiophene analogs that demonstrate good to excellent hH(3) affinities. Select analogs were profiled in a rat pharmacokinetic model.
Subject(s)
Histamine H3 Antagonists/chemical synthesis , Histamine H3 Antagonists/pharmacology , Indoles/chemical synthesis , Indoles/pharmacology , Thiophenes/chemical synthesis , Thiophenes/pharmacology , Animals , Ether-A-Go-Go Potassium Channels/drug effects , Histamine H3 Antagonists/pharmacokinetics , Indicators and Reagents , Indoles/pharmacokinetics , Isomerism , Models, Molecular , Rats , Structure-Activity Relationship , Thiophenes/pharmacokineticsABSTRACT
A novel series of imidazole containing histamine H(3) receptor ligands were investigated and found to be potent functional antagonists. After improving the stability of these molecules towards liver microsomes, these compounds were found to have no appreciable affinity for CYP P450s. Subsequent in vivo experiments showed significant brain uptake of (4-chloro-phenyl)-[2-(1-isopropyl-piperidin-4-ylmethoxy)-3-methyl-3H-imidazol-4-yl]-methanone 22.
Subject(s)
Blood-Brain Barrier/drug effects , Brain/drug effects , Chemistry, Pharmaceutical/methods , Histamine H3 Antagonists/chemistry , Histamine H3 Antagonists/chemical synthesis , Imidazoles/chemistry , Animals , Brain/metabolism , Drug Design , Drug Evaluation, Preclinical , Guinea Pigs , Histamine H3 Antagonists/metabolism , Humans , Ligands , Models, Chemical , Protein Binding , Rats , Structure-Activity RelationshipABSTRACT
The synthesis and biological activity of a new series of piperazine and diazepane amides is described. The new compounds are high affinity histamine H3 ligands and serotonin reuptake inhibitors.
Subject(s)
Azepines/chemical synthesis , Histamine H3 Antagonists/chemical synthesis , Piperazines/chemical synthesis , Selective Serotonin Reuptake Inhibitors/chemical synthesis , Amides/chemical synthesis , Amides/pharmacokinetics , Amides/pharmacology , Animals , Azepines/pharmacokinetics , Azepines/pharmacology , Brain/metabolism , Histamine H3 Antagonists/pharmacokinetics , Histamine H3 Antagonists/pharmacology , Humans , Piperazines/pharmacokinetics , Piperazines/pharmacology , Rats , Selective Serotonin Reuptake Inhibitors/pharmacokinetics , Selective Serotonin Reuptake Inhibitors/pharmacology , Structure-Activity RelationshipABSTRACT
Wake-promoting agents such as modafinil are used in the clinic as adjuncts to antidepressant therapy in order to alleviate lethargy. The wake-promoting action of histamine H(3) receptor antagonists has been evidenced in numerous animal studies. They may therefore be a viable strategy for use as an antidepressant therapy in conjunction with selective serotonin reuptake inhibitors. JNJ-28583867 (2-Methyl-4-(4-methylsulfanyl-phenyl)-7-(3-morpholin-4-yl-propoxy)-1,2,3,4-tetrahydro-isoquinoline) is a selective and potent histamine H(3) receptor antagonist (K(i)=10.6 nM) and inhibitor of the serotonin transporter (SERT) (K(i)=3.7 nM), with 30-fold selectivity for SERT over the dopamine and norepinephrine transporters. After subcutaneous administration, JNJ-28583867 occupied both the histamine H(3) receptor and the SERT in rat brain at low doses (<1 mg/kg). JNJ-28583867 blocked imetit-induced drinking (3-10 mg/kg i.p.), confirming in vivo functional activity at the histamine H(3) receptor and also significantly increased cortical extracellular levels of serotonin at doses of 0.3 mg/kg (s.c.) and higher. Smaller increases in cortical extracellular levels of norepinephrine and dopamine were also observed. JNJ-28583867 (3-30 mg/kg p.o.) showed antidepressant-like activity in the mouse tail suspension test. JNJ-28583867 (1-3 mg/kg s.c.) caused a dose-dependent increase in the time spent awake mirrored by a decrease in NREM. Concomitantly, JNJ-28583867 produced a potent suppression of REM sleep from the dose of 1 mg/kg onwards. JNJ-28583867 has good oral bioavailability in the rat (32%), a half-life of 6.9 h and a C(max) of 260 ng/ml after 10 mg/kg p.o. In summary, JNJ-28583867 is a combined histamine H(3) receptor antagonist-SERT inhibitor with in vivo efficacy in biochemical and behavioral models of depression and wakefulness.
Subject(s)
Histamine Antagonists/pharmacology , Receptors, Histamine H3/metabolism , Selective Serotonin Reuptake Inhibitors/pharmacology , Tetrahydroisoquinolines/pharmacology , Animals , Brain/drug effects , Brain/metabolism , CHO Cells , Cell Line , Cricetinae , Cricetulus , Dogs , Dopamine Plasma Membrane Transport Proteins/metabolism , Histamine Antagonists/pharmacokinetics , Humans , Male , Mice , Mice, Inbred BALB C , Norepinephrine Plasma Membrane Transport Proteins/metabolism , Rats , Rats, Sprague-Dawley , Serotonin Plasma Membrane Transport Proteins/metabolism , Selective Serotonin Reuptake Inhibitors/pharmacokinetics , Tetrahydroisoquinolines/pharmacokineticsABSTRACT
Two new series of 4-(1-alkyl-piperidin-4-yloxy)-benzonitriles and 4-(1-isopropyl-piperidin-4-yloxy)-benzylamines have been prepared. In vitro activity was determined at the recombinant human H(3) receptor and several members of these new series were found to be potent H(3) antagonists. The present compounds contain a 4-phenoxypiperidine core, which behaves as a conformationally restricted version of the 3-amino-1-propanol moiety common to the many previously described non-imidazole histamine H(3) ligands. One selected member of the new series, 4-[4-(1-isopropyl-piperidin-4-yloxy)-benzyl]-morpholine (13g), was found to be a potent, highly selective H(3) receptor antagonist with in vivo efficacy in a rat EEG model of wakefulness at doses as low as 1 mg/kg sc.
Subject(s)
Histamine Antagonists/chemical synthesis , Piperidines/chemical synthesis , Receptors, Histamine H3/drug effects , Animals , Autoradiography , Behavior, Animal/drug effects , Brain/drug effects , Brain/metabolism , Cell Line , Electroencephalography , Electromyography , Histamine Antagonists/chemistry , Histamine Antagonists/pharmacology , Humans , Male , Molecular Conformation , Piperidines/chemistry , Piperidines/pharmacology , Radioligand Assay , Rats , Rats, Sprague-Dawley , Sleep/drug effects , Structure-Activity Relationship , Wakefulness/drug effectsABSTRACT
4-(Aminoalkoxy)benzylamines were prepared and screened for in vitro activity at the human histamine H(3) receptor. Some members of this series exhibited subnanomolar binding affinities. Analogues in which one nitrogen atom was replaced with a methine group showed greatly reduced binding affinities. Six members of this series were found to be antagonists in a cell-based model of human histamine H(3) receptor activation. One member of this series, 1-[4-(3-piperidin-1-ylpropoxy)benzyl]piperidine (7b), was found to be a selective and potent human H(3) receptor antagonist.
Subject(s)
Benzylamines/chemical synthesis , Histamine Antagonists/chemical synthesis , Piperidines/chemical synthesis , Receptors, Histamine H3/drug effects , Animals , Benzylamines/metabolism , Benzylamines/pharmacology , Caco-2 Cells , Cell Line , Cerebral Cortex/metabolism , Cyclic AMP/biosynthesis , Histamine Antagonists/metabolism , Histamine Antagonists/pharmacology , Humans , In Vitro Techniques , Permeability , Piperidines/metabolism , Piperidines/pharmacology , Rats , Receptors, Histamine H3/metabolism , Structure-Activity RelationshipABSTRACT
The role of 5-HT7 receptor has been demonstrated in various animal models of mood disorders; however its function in cognition remains largely speculative. This study evaluates the effects of SB-269970, a selective 5-HT7 antagonist, in a translational model of working memory deficit and investigates whether it modulates cortical glutamate and/or dopamine neurotransmission in rats. The effect of SB-269970 was evaluated in the delayed non-matching to position task alone or in combination with MK-801, a non-competitive NMDA receptor antagonist, and, in separate experiments, with scopolamine, a non-selective muscarinic antagonist. SB-269970 (10 mg/kg) significantly reversed the deficits induced by MK-801 (0.1 mg/kg) but augmented the deficit induced by scopolamine (0.06 mg/kg). The ability of SB-269970 to modulate MK-801-induced glutamate and dopamine extracellular levels was separately evaluated using biosensor technology and microdialysis in the prefrontal cortex of freely moving rats. SB-269970 normalized MK-801 -induced glutamate but not dopamine extracellular levels in the prefrontal cortex. Rat plasma and brain concentrations of MK-801 were not affected by co-administration of SB-269970, arguing for a pharmacodynamic rather than a pharmacokinetic mechanism. These results indicate that 5-HT7 receptor antagonists might reverse cognitive deficits associated with NMDA receptor hypofunction by selectively normalizing glutamatergic neurotransmission.
Subject(s)
Cerebral Cortex/metabolism , Glutamic Acid/metabolism , Memory Disorders/drug therapy , Memory, Short-Term/drug effects , Receptors, Serotonin/metabolism , Synaptic Transmission/drug effects , Animals , Cerebral Cortex/drug effects , Dizocilpine Maleate/pharmacokinetics , Dizocilpine Maleate/therapeutic use , Male , Memory Disorders/metabolism , Phenols/pharmacokinetics , Phenols/therapeutic use , Rats , Rats, Sprague-Dawley , Serotonin Antagonists/pharmacokinetics , Serotonin Antagonists/therapeutic use , Sulfonamides/pharmacokinetics , Sulfonamides/therapeutic useABSTRACT
Histamine 3 (H(3)) receptors are distributed throughout the brain and regulate histamine as well as the activity of other neurotransmitters including acetylcholine (ACh). Impaired ACh neurotransmission is associated with deficits of cognitive-related functioning in many species including humans. The goal of these studies was to evaluate the behavioral and neurochemical effects of JNJ-10181457, a selective non-imidazole histamine H(3) receptor antagonist, in rats. The pharmacokinetic profile and receptor occupancy of JNJ-10181457 were tested. The efficacy of JNJ-10181457 was evaluated, acutely, in the imetit-induced water licking model, delayed non-matching to position (DNMTP) task and microdialysis studies. In addition, the effects of repeated administration of JNJ-10181457 were evaluated in the reversal learning task. A single administration of JNJ-10181457 (10 mg/kg, i.p.) resulted in significant plasma and brain exposure and maximal H(3) receptor occupancy. In addition, JNJ-10181457 reversed imetit-induced water licking, similarly to thioperamide (10 mg/kg, i.p.). In the DNMTP task, scopolamine (0.06 mg/kg, i.p.) significantly decreased percentage correct responding. These effects were significantly reversed by JNJ-10181457 (10 mg/kg, i.p.) and also by donepezil (1 mg/kg, i.p.), an acetylcholinesterase inhibitor, and were associated with normalization of ACh neurotransmission in the cortex. Repeated administration of JNJ-10181457 (10 mg/kg, i.p.) significantly increased percentage correct responding in the reversal learning task. Treatment discontinuation was not associated with rebound effects on cognition. These results indicate that selective blockade of histamine H(3) receptors might have therapeutic utility for the treatment of working memory deficits and learning disorders, especially those in which ACh neurotransmission is compromised.
Subject(s)
Acetylcholine/metabolism , Cognition/drug effects , Histamine Antagonists/pharmacology , Morpholines/pharmacology , Nootropic Agents/pharmacology , Piperidines/pharmacology , Receptors, Histamine H3/drug effects , Synaptic Transmission/drug effects , Animals , Anticonvulsants/pharmacology , Brain/drug effects , Brain/metabolism , Cholinesterase Inhibitors/pharmacology , Cognition/physiology , Conditioning, Operant/drug effects , Donepezil , Drinking Behavior/drug effects , Drinking Behavior/physiology , Drug Evaluation, Preclinical , Histamine Agonists/pharmacology , Histamine Antagonists/pharmacokinetics , Imidazoles/pharmacology , Indans/pharmacology , Learning/drug effects , Learning/physiology , Microdialysis , Morpholines/pharmacokinetics , Muscarinic Antagonists/pharmacology , Nootropic Agents/pharmacokinetics , Piperidines/pharmacokinetics , Rats , Rats, Sprague-Dawley , Scopolamine/pharmacology , Synaptic Transmission/physiology , Thiourea/analogs & derivatives , Thiourea/pharmacologyABSTRACT
A series of small molecules consisting of a heterocyclic core flanked by two basic functionalities were synthesized and screened for in vitro affinity at the human histamine H(3) receptor (hH(3)R). Nine of the twenty-eight compounds tested were found to possess a hH(3)R K(i) of less than 5 nM and consisted of a diverse range of central hetero-aromatic linkers (pyridine, pyrazine, oxazole, isoxazole, thiazole, furan, thiophene, and pyrrole). One member of this series, (4-isopropyl-piperazin-1-yl)-(6-piperidin-1-ylmethyl-pyridin-3-yl)-methanone (37), was found to be a high affinity, selective antagonist that crosses the blood-brain barrier and occupies H(3) receptors after oral administration in the rat.
Subject(s)
Diamines/chemistry , Diamines/pharmacology , Histamine H3 Antagonists/chemistry , Histamine H3 Antagonists/pharmacology , Receptors, Histamine H3/metabolism , Animals , Blood-Brain Barrier/drug effects , Cell Line , Diamines/pharmacokinetics , Histamine H3 Antagonists/pharmacokinetics , Humans , Protein Binding , Rats , Rats, Sprague-DawleyABSTRACT
5-HT7 receptors have been linked to a number of psychiatric disorders including anxiety and depression. The localization of 5-HT7 receptors in the thalamus, a key sensory processing center, and the high affinity of many atypical antipsychotic compounds for these receptors have led to the speculation of the utility of 5-HT7 antagonists in schizophrenia. The goal of these studies was to examine the effects of pharmacologic blockade and genetic ablation of 5-HT7 receptors in animal models predictive of antipsychotic-like activity. We evaluated the effects of SB-269970, a selective 5-HT7 receptor antagonist, on amphetamine and ketamine-induced hyperactivity and prepulse inhibition (PPI) deficits. In addition, sensorimotor gating function and locomotor activity were evaluated in 5-HT7 knockout mice. Locomotor activity was measured for up to 180 min using an automated infrared photobeam system, and PPI was evaluated in startle chambers. SB-269970 (3, 10 and 30 mg/kg, intraperitoneally) significantly blocked amphetamine [3 mg/kg, subcutaneously (s.c.)] and ketamine (30 mg/kg, s.c.)-induced hyperactivity and reversed amphetamine (10 mg/kg, s.c.)-induced but not ketamine (30 mg/kg, s.c.)-induced PPI deficits, without changing spontaneous locomotor activity and startle amplitude. The largest dose of SB-269970 did not block the effects of amphetamine in 5-HT7 knockout mice. Collectively, these results indicate that blockade of 5-HT7 receptors partially modulates glutamatergic and dopaminergic function and could be clinically useful for the treatment of positive symptoms of schizophrenia.
Subject(s)
Antipsychotic Agents/pharmacology , Brain/drug effects , Disease Models, Animal , Phenols/pharmacology , Psychotic Disorders/psychology , Receptors, Serotonin/drug effects , Sulfonamides/pharmacology , Amphetamine/pharmacology , Animals , Arousal/drug effects , Dopamine/metabolism , Dose-Response Relationship, Drug , Glutamine/metabolism , Injections, Intraperitoneal , Injections, Subcutaneous , Ketamine/pharmacology , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Motor Activity/drug effects , Receptors, Serotonin/genetics , Reflex, Startle/drug effects , Synaptic Transmission/drug effectsABSTRACT
A series of tetrahydroisoquinolines acting as dual serotonin transporter inhibitor/histamine H(3) antagonists is described. The introduction of polar aromatic spacers as part of the histamine H(3) pharmacophore was explored. A convergent synthesis of the final products allowing late stage introduction of the aromatic side chain was developed. In vitro and in vivo data are discussed.
Subject(s)
Histamine Antagonists/chemical synthesis , Histamine Antagonists/pharmacology , Receptors, Histamine H3/drug effects , Serotonin Antagonists/chemical synthesis , Serotonin Antagonists/pharmacology , Serotonin Plasma Membrane Transport Proteins/drug effects , Tetrahydroisoquinolines/chemical synthesis , Tetrahydroisoquinolines/pharmacology , 5-Hydroxytryptophan/pharmacology , Animals , Brain/metabolism , Drug Design , Humans , Indicators and Reagents , Rats , Structure-Activity RelationshipABSTRACT
The design, synthesis, and in vitro activity of a series of novel 5-ethynyl-2-aryloxybenzylamine-based histamine H(3) ligands that are also serotonin reuptake transporters is described.
Subject(s)
Benzylamines/chemistry , Chemistry, Pharmaceutical/methods , Histamine Antagonists/chemical synthesis , Histamine Antagonists/pharmacology , Receptors, Histamine H3/chemistry , Selective Serotonin Reuptake Inhibitors/pharmacology , Animals , Antidepressive Agents/pharmacology , Drug Design , Humans , Kinetics , Models, Chemical , Protein Binding , Rats , Selective Serotonin Reuptake Inhibitors/chemistryABSTRACT
A series of novel and potent 6-heteroaryl-pyrrolidino-tetrahydroisoquinolines with dual histamine H(3) antagonist/serotonin transporter inhibitor activity is described. In vitro and in vivo data are discussed.
Subject(s)
Histamine H1 Antagonists/pharmacology , Pyrrolidines/pharmacology , Receptors, Histamine H3/drug effects , Serotonin Plasma Membrane Transport Proteins/drug effects , Tetrahydroisoquinolines/pharmacology , Animals , Blood-Brain Barrier , Histamine H1 Antagonists/chemistry , Mice , Pyrrolidines/chemistry , Structure-Activity Relationship , Tetrahydroisoquinolines/chemistryABSTRACT
A series of novel tetrahydronaphthyridine-based histamine H(3) ligands that have serotonin reuptake transporter inhibitor activity is described. The 1,2,3,4-tetrahydro-2,6-naphthyridine scaffold is assembled via the addition of a nitrostyrene to a metalated pyridine followed by reduction and cyclization to form the naphthyridine. In vitro biological data for these novel compounds are discussed.
Subject(s)
Chemistry, Pharmaceutical/methods , Histamine Antagonists/chemical synthesis , Histamine Antagonists/pharmacology , Histamine/chemistry , Naphthyridines/chemical synthesis , Receptors, Histamine H3/chemistry , Selective Serotonin Reuptake Inhibitors/chemical synthesis , Animals , Drug Design , Humans , Models, Chemical , Molecular Conformation , Naphthyridines/pharmacology , Rats , Serotonin/metabolism , Selective Serotonin Reuptake Inhibitors/pharmacologyABSTRACT
The synthesis and structure-activity relationships of a series of novel phenoxyphenyl diamine derivatives with affinity for both the histamine H(3) receptor and the serotonin transporter is described.
Subject(s)
Diamines/chemistry , Histamine Antagonists/chemistry , Histamine Antagonists/pharmacology , Receptors, Histamine H3/drug effects , Selective Serotonin Reuptake Inhibitors/chemistry , Selective Serotonin Reuptake Inhibitors/pharmacology , Histamine Antagonists/chemical synthesis , Humans , Molecular Structure , Receptors, Histamine H3/chemistry , Selective Serotonin Reuptake Inhibitors/chemical synthesis , Structure-Activity RelationshipABSTRACT
A series of tetrahydroisoquinolines acting as dual histamine H3/serotonin transporter ligands is described. A highly regio-selective synthesis of the tetrahydroisoquinoline core involving acid mediated ring-closure of an acetophenone intermediate followed by reduction with NaCNBH3 was developed. In vitro and in vivo data are discussed.
Subject(s)
Receptors, Histamine H3/chemistry , Receptors, Histamine H3/drug effects , Serotonin Plasma Membrane Transport Proteins/drug effects , 5-Hydroxytryptophan/pharmacology , Animals , Behavior, Animal/drug effects , Humans , Isoquinolines/chemical synthesis , Isoquinolines/pharmacology , Ligands , Mice , Piperazines/chemical synthesis , Piperazines/pharmacology , Rats , Structure-Activity RelationshipABSTRACT
A series of novel and potent pyrrolidino-tetrahydroisoquinolines with dual histamine H(3) antagonist/serotonin transporter inhibitor activity is described. A highly regio- and diastereoselective synthesis of the pyrrolidino-tetrahydroisoquinoline core involving acid mediated ring-closure of an acetophenone intermediate followed by reduction with NaCNBH(3) was developed. In vitro and in vivo data are discussed.
Subject(s)
Chemistry, Pharmaceutical/methods , Histamine Antagonists/chemical synthesis , Histamine Antagonists/pharmacology , Receptors, Histamine H3/chemistry , Selective Serotonin Reuptake Inhibitors/chemical synthesis , Selective Serotonin Reuptake Inhibitors/pharmacology , Serotonin/chemistry , Tetrahydroisoquinolines/chemical synthesis , Tetrahydroisoquinolines/pharmacology , Animals , Depression/drug therapy , Drug Design , Humans , Kinetics , Models, Chemical , Molecular Conformation , RatsABSTRACT
A series of novel 4-aryl-1,2,3,4-tetrahydroisoquinoline-based histamine H(3) ligands that also have serotonin reuptake transporter inhibitor activity is described. The synthesis, in vitro biological data, and select pharmacokinetic data for these novel compounds are discussed.
Subject(s)
Histamine Antagonists/chemical synthesis , Histamine Antagonists/pharmacology , Receptors, Histamine H3/drug effects , Selective Serotonin Reuptake Inhibitors/chemical synthesis , Selective Serotonin Reuptake Inhibitors/pharmacology , Tetrahydroisoquinolines/chemical synthesis , Tetrahydroisoquinolines/pharmacology , Animals , Crystallography, X-Ray , Dopamine Plasma Membrane Transport Proteins/drug effects , Dopamine Plasma Membrane Transport Proteins/metabolism , Half-Life , Humans , Indicators and Reagents , Models, Molecular , Molecular Conformation , Norepinephrine/metabolism , Rats , Serotonin Plasma Membrane Transport Proteins/drug effects , Serotonin Plasma Membrane Transport Proteins/metabolism , Selective Serotonin Reuptake Inhibitors/pharmacokinetics , Structure-Activity Relationship , Tetrahydroisoquinolines/pharmacokineticsABSTRACT
Aplysamine-1 (1), a marine natural product, was synthesized and screened for in vitro activity at the human and rat histamine H3 receptors. Aplysamine-1 (1) was found to possess a high binding affinity for the human H3 receptor (Ki = 30+/-4 nM). Synthetic analogs of 1, including des-bromoaplysamine-1 (10) and dimethyl-{2-[4-(3-piperidin-1-yl-propoxy)-phenyl]-ethyl}-amine (13), were potent H3 antagonists.