ABSTRACT
RATIONALE: Vasopressin (AVP) plays a role in regulating anxiety, which is thought to be partially mediated through the V1a receptor. Recently, JNJ-17308616 was identified as a V1a antagonist. OBJECTIVES: The purpose of this work was to assess V1a receptor affinity and selectivity of JNJ-17308616 and in vivo efficacy in animal models of anxiety-like behavior. MATERIALS AND METHODS: The affinity of JNJ-17308616 for the human and rat V1a, V1b, V2, and oxytocin receptors was determined. Central administration of AVP induces a scratching response mediated through the V1a receptor. Inhibition of scratching was used as a behavioral measure of in vivo potency. JNJ-17308616 was tested in five models of anxiety: rat elevated plus-maze (EPM), rat-elevated zero-maze (EZM), rat-conditioned lick suppression (CLS), rat pup separation-induced ultrasonic vocalizations (USV), and mouse marble burying (MMB). RESULTS: High affinity for the human V1a receptor (K (i) 5.0 nM) was confirmed. However, the rat V1a receptor affinity was more modest (K (i) 216 nM), and the compound was not selective over the rat V2 receptor (K (i) 276 nM). At 100 mg/kg, JNJ-17308616 significantly reduced anxiety-like behavior in EPM, USV, and MMB; at 30 mg/kg, it was effective in EZM and CLS. JNJ-17308616 neither impaired social recognition nor reduced locomotor activity. CONCLUSIONS: These results demonstrate the potential for V1a receptor antagonists as novel anxiolytics. Tool compounds that have greater V1a receptor selectivity than JNJ-17308616 are necessary to make precise conclusions about the role of the V1a receptor in affective disorders.
Subject(s)
Anti-Anxiety Agents/pharmacology , Antidiuretic Hormone Receptor Antagonists , Anxiety/psychology , Behavior, Animal/drug effects , Animals , Arginine Vasopressin/pharmacology , Conditioning, Operant/drug effects , Dose-Response Relationship, Drug , Female , Male , Mice , Mice, Knockout , Motor Activity/drug effects , Ovariectomy , Rats , Rats, Sprague-Dawley , Receptors, Vasopressin/genetics , Recognition, Psychology/drug effects , Social Behavior , Spiro Compounds/pharmacology , Vasopressins/metabolism , Vocalization, Animal/drug effectsABSTRACT
Vasopressin and corticotropin releasing factor (CRF) are both critical regulators of an animal's stress response and have been linked to anxiety and depression. As such, antagonists of the CRF1 and V1b receptor subtypes are being developed as potential treatments for affective disorders. The two most characterized V1b and CRF1 antagonists are SSR149415 and CP-154,526, respectively, and the present studies were designed to compare these two compounds in acute animal models of affective disorders. We employed five anxiety models: Separation-induced pup vocalizations (guinea pig and rat), elevated plus-maze (EPM), conditioned lick suppression (CLS), and marble burying (mouse); as well as three depression models: forced swim test (FST; mouse and rat) and tail suspension test (TST; mouse). SSR149415 (1-30 mg/kg) was active in the vocalization, EPM and CLS models, but inactive in marble burying. CP-154,526 (1-30 mg/kg) was active in vocalization models, but inactive in EPM, CLS, and marble burying. SSR149415 was inactive in all depression models; CP-154,526 was active in rat FST but inactive in mouse models. This work demonstrates the different profiles of V1b and CRF1 receptor antagonists and supports both approaches in the treatment of affective disorders.
Subject(s)
Antidiuretic Hormone Receptor Antagonists , Anxiety/drug therapy , Depression/drug therapy , Indoles/pharmacology , Pyrimidines/pharmacology , Pyrroles/pharmacology , Pyrrolidines/pharmacology , Receptors, Corticotropin-Releasing Hormone/antagonists & inhibitors , Animals , Anxiety/metabolism , Anxiety/psychology , Conditioning, Psychological/drug effects , Depression/metabolism , Depression/psychology , Female , Guinea Pigs , Humans , Male , Maze Learning/drug effects , Mice , Rats , Receptors, Corticotropin-Releasing Hormone/metabolism , Receptors, Vasopressin/metabolism , Vocalization, Animal/drug effectsABSTRACT
RATIONALE: Previous studies have demonstrated behaviors indicative of anxiolysis in rats pretreated with the nociceptin receptor (opioid receptor like-1, ORL-1) agonist, Ro64-6198. OBJECTIVES: The aim of this study was to examine the effects of Ro64-6198 in anxiety models across three species: rat, guinea pig, and mouse. In addition, the receptor specificity of Ro64-6198 was studied, using the ORL-1 receptor antagonist, J-113397, and ORL-1 receptor knockout (KO) mice. Finally, neurological studies examined potential side effects of Ro64-6198 in the rat and mouse. RESULTS: Ro64-6198 (3-10 mg/kg) increased punished responding in a rat conditioned lick suppression test similarly to chlordiazepoxide (6 mg/kg). This effect of Ro64-6198 was attenuated by J-113397 (10 mg/kg), but not the mu opioid antagonist, naltrexone (3 mg/kg). In addition, Ro64-6198 (1-3 mg/kg) reduced isolation-induced vocalizations in rat and guinea pig pups. Ro64-6198 (3 mg/kg) increased the proportion of punished responding in a mouse Geller-Seifter test in wild-type (WT) but not ORL-1 KO mice, whereas diazepam (1-5.6 mg/kg) was effective in both genotypes. In rats, Ro64-6198 reduced locomotor activity (LMA) and body temperature and impaired rotarod, beam walking, and fixed-ratio (FR) performance at doses of 10-30 mg/kg, i.e., three to ten times higher than an anxiolytic dose. In WT mice, Ro64-6198 (3-10 mg/kg) reduced LMA and rotarod performance, body temperature, and FR responding, but these same measures were unaffected in ORL-1 KO mice. Haloperidol (0.3-3 mg/kg) reduced these measures to a similar extent in both genotypes. These studies confirm the potent, ORL-1 receptor-mediated, anxiolytic-like effects of Ro64-6198, extending the findings across three species. Ro64-6198 has target-based side effects, although the magnitude of these effects varies across species.
Subject(s)
Anti-Anxiety Agents/pharmacology , Arousal/drug effects , Imidazoles/pharmacology , Receptors, Opioid/agonists , Spiro Compounds/pharmacology , Animals , Anti-Anxiety Agents/toxicity , Benzimidazoles/pharmacology , Chlordiazepoxide/pharmacology , Conditioning, Classical/drug effects , Dose-Response Relationship, Drug , Female , Guinea Pigs , Imidazoles/toxicity , Male , Mice , Mice, Knockout , Motor Activity/drug effects , Narcotic Antagonists , Piperidines/pharmacology , Rats , Species Specificity , Spiro Compounds/toxicity , Vocalization, Animal/drug effects , Nociceptin ReceptorABSTRACT
The present studies were designed to assess whether the novel muscarinic M(2) receptor antagonist 4-cyclohexyl-alpha-[4[[4-methoxyphenyl]sulphinyl]-phenyl]-1-piperazineacetonitrile (SCH 57790) could increase acetylcholine release in the central nervous system (CNS) and enhance cognitive performance in rodents and nonhuman primates. In vivo microdialysis studies show that SCH 57790 (0.1-10 mg/kg, p.o.) produced dose-related increases in acetylcholine release from rat hippocampus, cortex, and striatum. SCH 57790 (0.003-1.0 mg/kg) increased retention times in young rat passive avoidance responding when given either before or after training. Also, SCH 57790 reversed scopolamine-induced deficits in mice in a passive avoidance task. In a working memory operant task in squirrel monkeys, administration of SCH 57790 (0.01-0.03 mg/kg) improved performance under a schedule of fixed-ratio discrimination with titrating delay. The effects observed with SCH 57790 in behavioral studies were qualitatively similar to the effects produced by the clinically used cholinesterase inhibitor donepezil, suggesting that blockade of muscarinic M(2) receptors is a viable approach to enhancing cognitive performance.
