Avaliação da preferência alimentar e dos sistemas dopaminérgico e endocanabinoide no modelo de programação pelo desmame precoce em ratos Wistar de ambos os sexos

Abstract

Early weaning (EW) is a risk factor for obesity and its comorbidities later in life. Here, we investigated the association between EW and changes in feeding behavior, dopaminergic and endocannabinoid systems in adult rats of both sexes. For this, lactating rats and pups (3 males and 3 females) were divided into 2 groups: EW (EW), dams were wrapped with a bandage interrupting suckling in the last 3 days of breastfeeding; control, dams whose pups ingested milk throughout breastfeeding. At 175 days of age, a food challenge was performed: male and female offspring of C and EW groups could freely self-select between high-fat and high-sugar diets.EW males preferred high-fat diet at 30 min although they ate more high-sugar diet after 12 h. EW females did not show differences in the preference between the palatable diets. At 180 days of age, offspring were killed andproteins of dopaminergic and endocannabinoid systems were measured by Western blotting. EW offspring from both sexes showed hyperphagia. EW males showed lower type 2 dopamine receptor (D2r) in nucleus accumbens (NAc) and dorsal striatum (DS), while EW females had lower tyrosine hydroxylase in ventral tegmental area and NAc, D1r in NAc and D2r in prefrontal cortex. In lateral hypothalamus, EW males presented lower fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase, while the EW females showed lower N-arachidonyl-phosphatidylethanolamine phospholipase-D (NAPE-PLD) and higher FAAH. The EW alters both dopaminergic and endocannabinoid systems parameters at adulthood, contributing to the eating disorder of the progeny in a sex-dependent manner.