ABSTRACT
BACKGROUND: Serotonin (5-HT) is involved in nervous system ontogenesis, and is important for neurotransmission and behavior modulation after the developmental stage. Alterations in 5-HT levels during the early period of life may signal to feeding behavior and hypothalamic genic expression changes in adulthood. OBJECTIVES: Investigate the effects of hypercaloric diet in adult rats submitted to neonatal serotonin reuptake inhibition on food intake, fat pad mass, plasmatic triglycerides/cholesterol and gene expression of hypothalamic peptides (POMC, NPY) and serotonin receptors (5-HT1B, 5-HT2C). METHODS: In each litter, 8 pups were divided into two groups: control (C) and fluoxetine (F). From the 1(st) to the 21(st) postnatal day, C pups received sterile saline while F pups received fluoxetine (10mg/kg). From 180 to 215 days, a group of rats from C and F groups were fed hypercaloric diet (CH and FH, 421.4Kcal/100 g) while the rest of animals from C and F groups fed chow diet (CC and FC). RESULTS: The use of hypercaloric diet was associated with lower accumulation of white adipose tissue in adult rats subjected to neonatal serotonin reuptake inhibition. Adult rats of group FC showed decreased 5-HT2C and neuropeptide Y mRNA expression compared with control chow diet group (CC). After chronic use of a hypercaloric diet, the expression of 5-HT2C was higher in the FH group than the FC group and neuropeptide Y expression decreased in FH related to FC. CONCLUSIONS: These findings suggest that neonatal serotonin reuptake inhibition is associated with better adaptation to hypercaloric diet in adult rats.