Anti-Obsessional and Antidepressant Profile of Besipirdine

Halothane-anesthetized rabbit: a new experimental model to test the effects of besipirdine and duloxetine on lower urinary tract function

INTRODUCTION

The effects of besipirdine and its main metabolite, HP-748, as well as duloxetine and tomoxetine in the lower urinary tract (LUT) were studied using in vitro and in vivo techniques.

MATERIALS AND METHODS

For in vivo studies, besipirdine or duloxetine effects on cystometric parameters and striated sphincter electromyographic (SS-EMG) activity were investigated. On the isolated urethra, norepinephrine (NE) concentration-response curves (CRC) were performed in the presence of besipirdine, duloxetine or tomoxetine. Moreover, CRC to HP-748 were constructed in the absence or presence of prazosin. Potency (pEC(50)) and maximal responses (E(max)) were determined.

RESULTS

Besipirdine at 1, 3 and 5 mg/kg intravenously (i.v.) induced a significant increase in SS-EMG activity (250, 273 and 241%, respectively), bladder capacity (172, 197, and 235%, respectively), intercontraction interval (ICI; 208, 242, and 400%, respectively), and residual volume (181, 191, and 236%, respectively). Duloxetine at 2 mg/kg i.v. increased significantly SS-EMG activity (219%), micturition volume (222%), and ICI (205%). In the isolated urethra, besipirdine, tomoxetine and duloxetine significantly displaced to the left the NE CRC. In addition, HP-748 induced contraction of the isolated urethra with a pEC(50) of 5.89 and an E(max) of 37%.

CONCLUSIONS

These data support the potential of besipirdine as a new drug for LUT dysfunctions such as stress and mixed urinary incontinence.

Animal models with potential applications for screening compounds for the treatment of obsessive-compulsive disorder

The availability of an animal model for obsessive-compulsive disorder (OCD) is necessary for the development of novel pharmacological treatments. To be useful, the model must be predictive of clinical performance, possess characteristic criteria and distinguish anti-OCD from antidepressant compounds. Due to the lack of OCD models useful for drug discovery, all compounds currently used for OCD were developed first as antidepressants. In this article, we discuss the relative merits of: stereotypic behaviours (canine acral lick, feather picking, amphetamine- and 5-HT-induced stereotypy); adjunctive and displacement behaviours (schedule-induced polydipsia, wheel running, resident-intruder grooming); anxiolytic tests (separation and shock-induced ultrasonic vocalisation and marble burying); and depression tests (inescapable shock-induced escape and immobility in forced swim) as potential OCD models. We conclude that adjunctive and displacement behaviours, and in particular schedule-induced polydipsia, may prove to be the best models for compulsive behaviour in animals that can be used for the discovery of novel anti-OCD agents.