Pharmacotherapy of diet-restriction-induced-anorexia nervosa with fluoxetine in rats

Diet is an important factor in the control and improvement of various psychological problems such as depression, anxiety, hyperactivity and behavioral impulsivity. Anorexia Nervosa (AN) is a psychological problem that occurs most commonly in adolescent females although men are also susceptible. The patients exhibit self-imposed, reduced body weight, anxiety, hyperactivity and behavioral impulsivity. The involvement of 5-hydroxytryptamine (5-HT) in the regulation of hunger and mood is well documented. Studies have shown that the hyperactivity elicited by diet restrictions (DR) could result from increased sensitization of somatodendritic 5-HT1Aautoreceptors, thus leading to a decreased brain serotonin turnover. Fluoxetine; a Selective Serotonin Reuptake Inhibitor (SSRI) is, generally, used as an antidepressant. Fluoxetine increases extracellular serotonin levels by inhibiting its reuptake from the synaptic cleft and later by desensitization of 5-HT-1A somatodendritic autoreceptors in the brain. The present experiment is designed to monitor the effects of fluoxetine administration to desensitized 5-HT1A receptors that may increase serotonin concentration in DR rats. Results may be helpful to inhibit behavioral deficits induced by diet-restriction-induced AN in rats. Methods: Fluoxetine at low dose and high dose was given orally to respective freely fed or diet restricted animals daily for five weeks. Behavioral activities were also monitored weekly. Results: Fluoxetine (at a low dose and high dose) increased significantly food intake and body weight in diet restricted rats. Fluoxetine also produced anxiolytic-like effects in DR rats measured as decreased activity in the open field and increased time spent in the light compartment. This might be associated with increased serum tryptophan and brain serotonin metabolism. Conclusion: It is concluded that the Pharmacological agents which increased serotonin availability or desensitizing 5-HT1A receptors are likely to improve behavioral deficits and psychological problems associated with anorexia nervosa.