Objectives: 

Central serotonin (5-HT) has been well documented to induce an attenuation of food intake in mammals. Among all 5-HT receptors described, the 5-HT1B and 5HT2C receptor subtypes were shown to be the principal mediators through which serotonin exerts its anorexigenic effects. In fish, it has also been shown that 5-HT has an inhibitory role on feeding and, in previous studies from our laboratory using rainbow trout as animal model, we demonstrated that 5-HT1A and 5-HT2C receptor agonists produce reductions in food intake. The aim of this work was to further evaluate the effect of two 5-HT1B receptor agonists on food intake in rainbow trout.

Materials: 

A first experiment consisted in the intraperitoneal (i.p.) administration of anpirtoline (2 mg/kg) and in a second experiment two doses (100 ug/kg; 200 ug/kg) of the agonist CP93129 were intracerebroventricularly (i.c.v.) injected. Food intake was quantified 2, 4 and 24 hours after administration of the agonists. The data from experiments were analyzed by one-way ANOVA followed by Student–Newman–Keuls test for multiple comparisons (P <0.05)

Results: 

The results obtained show that the administration of anpirtoline as well as both doses of CP93129 had no effect on food intake at any assayed time when compared with their corresponding control fish.

Conclusions: 

These results suggest that the 5-HT1B-like receptor does not participate in the short-term anorexigenic action of 5-HT in the rainbow trout.