IMPACT OF PERINATAL OVERFEEDING ON BODY MASS OF FEMALE WISTAR RATS

Abstract

Childhood obesity is an important independent risk factor for later metabolic diseases, such as
type 2 diabetes, dyslipidemia, and arterial hypertension. However, males and females
respond differently to this nutritional challenge. Here, we propose an experimental study of
the effects of early obesity, using the litter reduction model, in the body mass of female adult
Wistar rats. The litters were delivered on postnatal day 0 - PN0. In PN2, the offspring of
Wistar rats was standardized in 9 (normal litter – NL) and 3 (reduced litter – SL) pups.
Animals were weaned at PN21 and kept at 3 per cage for both groups until PN120. In PN120,
the rats were weighed and euthanized, and then the tissues were collected, according to the
approval of the Ethics in Animal Use Committee n° 4831020822. Our data points to a body
weight difference in PN21 between the groups, where the SL group was overweight compared
to the NL group (p<0.0001). In PN120, the SL group continued with a higher weight than the
NL group (p <0.01). SL rats showed increased weight in periovarian, periuterine,
retroperitoneal, mesenteric and brown fat (p=0.002, p<0.0001, p=0.001, p=0.002 and
p=0.0001, respectively) compared to NL animals. Taken together, the present data shows that
females Wistar rats are vulnerable to the effects of early in life obesity on body mass, leading
to a greater predisposition to later risk factors associated with obesity.