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
Galanin mediates diverse physiological functions in digestive, endocrine, and central nervous systems through G-protein-coupled receptors. Two galanin receptors have been cloned but the gene structures are unknown. We report genomic and cDNA cloning of the mouse GalR1 galanin receptor and demonstrate that the coding sequence is uniquely divided into three exons encoding the N-terminal portion through the fifth transmebrane domain, the third intracellular loop, and the sixth transmembrane domain through the C-terminus. Functional analysis of the encoded cDNA revealed active ligand binding and intracellular signaling. The expression is detected in brain, spinal cord, heart and skeletal muscle.
