ABSTRACT
Epidemiological research indicates that sildenafil (Viagra) abuse is associated with increased risk behaviors. The present study employs the open field, a standard animal model used in the field of anxiety research, to examine whether chronic exposure to sildenafil affects anxiety and risk-taking behaviors in gonadally intact and castrated male Wistar rats. Sildenafil (10 mg/kg) or saline were administered three times a week for three weeks. Animals were tested once a week in the open field during and after drug treatment. Sildenafil treatment increased the number of center entries and time spent in the center in intact and castrated animals during and after treatment, suggesting that repeated drug use decreases anxiety. Sildenafil also restored the deficits in exploration and locomotion produced by castration, indicating that sildenafil effects on open field behaviors are independent of endogenous androgens. We caution against generalizing from this study to human behaviors, but propose that the behavioral effects produced by a chronic high dose of sildenafil warrant further studies into its abuse potential.
Subject(s)
Anxiety/prevention & control , Anxiety/psychology , Castration , Phosphodiesterase Inhibitors/pharmacology , Piperazines/pharmacology , Sulfones/pharmacology , Animals , Drug Administration Schedule , Male , Phosphodiesterase Inhibitors/administration & dosage , Piperazines/administration & dosage , Purines/administration & dosage , Purines/pharmacology , Random Allocation , Rats , Rats, Wistar , Sildenafil Citrate , Sulfones/administration & dosageABSTRACT
Estudios epidemiológicos indican que el abuso de sildenafil (Viagra) está asociado con comportamientos de riesgo. En el presente estudio utilizamos el campo abierto, un modelo animal estándar en investigaciones sobre la ansiedad, para examinar los efectos de la administración crónica de sildenafil sobre la ansiedad y comportamientos de riesgo en ratas machos Wistar intactas y castradas. Sildenafil (10 mg/kg) o suero salino fueron administrados tres veces semanalmente durante tres semanas. Se midió el comportamiento en el campo abierto una vez por semana durante y posteriormente al tratamiento. El tratamiento con sildenafil incrementó las entradas al centro del campo y el tiempo en el centro en animales intactos y castrados, lo que sugiere que la administración crónica disminuye la ansiedad. Sildenafil también restauró los déficit asociados con la castración, lo que indica que los efectos de sildenafil sobre comportamientos en el campo abierto son independientes de la presencia de andrógenos endógenos. Alertamos en contra de generalizar estos resultados a los comportamientos humanos, pero proponemos que los efectos conductuales que produce la administración crónica de una dosis alta de sildenafil justifican el estudio del potencial de abuso de esta sustancia
Epidemiological research indicates that sildenafil (Viagra) abuse is associated with increased risk behaviors. The present study employs the open field, a standard animal model used in the field of anxiety research, to examine whether chronic exposure to sildenafil affects anxiety and risk-taking behaviors in gonadally intact and castrated male Wistar rats. Sildenafil (10 mg/kg) or saline were administered three times a week for three weeks. Animals were tested once a week in the open field during and after drug treatment. Sildenafil treatment increased the number of center entries and time spent in the center in intact and castrated animals during and after treatment, suggesting that repeated drug use decreases anxiety. Sildenafil also restored the deficits in exploration and locomotion produced by castration, indicating that sildenafil effects on open field behaviors are independent of endogenous androgens. We caution against generalizing from this study to human behaviors, but propose that the behavioral effects produced by a chronic high dose of sildenafil warrant further studies into its abuse potential