Abstract
Early weaning (EW) is a risk factor for metabolic syndrome. Male rats that were
precociously weaned present neonatal malnutrition and, in adulthood, developed
overweight, accumulation of body fat, dyslipidemia, changes in glycemic
homeostasis, hyperleptinemia, and increase of vitamin D. As metabolic profile of
early-weaned females is not known, we investigated the endocrine-metabolic
parameters in adolescence and adult female rats of 2 different EW models. Wistar
lactating rats and pups from both sexes were separated into 3 groups:
non-pharmacological EW (NPEW), dams were involved with a bandage interrupting
suckling in the last 3 days of lactation; pharmacological EW (PEW), dams were
bromocriptine-treated (0.5 mg/twice a day via intraperitoneal
injection) for 3 days before weaning; and control, dams whose pups ate milk
throughout lactation. At 21 days-old, NPEW and PEW females had lower body
weight. At 180 days-old, NPEW and PEW females showed higher feed efficiency,
weight gain, body fat percentage, and greater accumulation of gonadal and
retroperitoneal fat depots associated with adipocyte hypertrophy. NPEW females
also showed hyperphagia. Only NPEW females presented hyperleptinemia. Plasma
thyroid hormones and vitamin D were unchanged among EW females. Regarding sex
hormones, at 45 days-old, no change was found in EW females, while at 180
days-old, PEW females had hypoestrogenemia. EW increases the risk for obesity in
female rats in adulthood, as already demonstrated for males, although through
distinct mechanisms involving some hormones.
Key words
developmental plasticity - fat mass - leptin - vitamin D - thyroid hormones
