Ovarian steroids counteract serotonergic drugs actions in an animal model of obsessive-compulsive disorder

Recently, we reported the existence of differences according to the reproductive stage of female rats in a pharmacologically induced animal model of obsessive-compulsive disorder. Therefore, the aim of the present study was to examine the role of endogenous and exogenous ovarian steroids in the induction of perseverative responses in a T-maze by the 5-HT1A agonist 8-OH-DPAT (1.0 and 2.0 mg/kg, SC) and in the preventive action of the selective serotonin reuptake inhibitor, fluoxetine (10.0 mg/kg, three times, SC). The results showed that the perseverant action of 8-OH-DPAT as well as the prevention of such perseverance by fluoxetine were reduced during the estrous-metestrous phases of the female reproductive cycle, and by the exogenous ovarian steroids administration to ovariectomized animals. Data are discussed from the standpoint of the action of ovarian steroids on the serotonergic system and on the putative influence of these hormones on the physiopathology and treatment of this disorder in women. (c) 2006 Elsevier Ltd. All rights reserved.