Effetti indotti dal PD 128907, potente agonista D3, sulla sequenza di sazietà, nel ratto

The fixed behavioral sequence exhibited by rat in response to food ingestion is called behavioral satiety sequence (BSS): cessation of feeding is followed by a period of grooming and activity endings with a period of resting. This profile of BSS is closely linked to satiety. In different experimental design, BSS has been used to investigate whether reduction of food intake, induced by different drugs like D1 and D2 receptor agonist, was determined by an influence on processes underlying satiety or on specific behaviors associated to feeding. Our recent data have shown that PD 128907, a D3 receptor agonist, produced a decrease of food intake. In order to assess the mechanism involved in D3 receptors control of feeding, an experiment was performed in which effect of PD 128907 was analysed on BSS. Male Wistar rats, injected IP with different dosages of PD 128907, were used. Our data show that PD 128907, determined an altered pattern of BSS with significative increases of activity duration and decreases of the resting one. This result suggests that hyperactivity may represent one of the possible mechanisms of food intake inhibition caused by D3 receptor manipulation.