title: Early exposure to a high-fat diet has more drastic consequences on metabolism compared with exposure during adulthood in rats.
abstract: The aim of this study was determine whether the introduction of a high-fat diet during the peripubertal phase induces significant changes in body weight control, glucose homeostasis and the parasympathetic tonus compared with the administration of this diet to adult rats. High-fat diet was offered to male Wistar rats at weaning or during adulthood. A group of rats received high-fat diet for 60 days, from weaning to 81-day-old (HF81) or from 60 to 120-day-old (HF120), whereas 2 other groups received a normal-fat diet (i. e., NF81 and NF120). We analyzed adiposity, glucose homeostasis, insulin sensitivity, and vagal nerve activity. High-fat diet increased the accumulation of adipose tissue in all of the rats, but the difference was greater in the rats that were fed the high-fat diet since weaning (p<0.001). The HF rats showed glucose intolerance with high levels of insulin secretion during the glucose tolerance test (p<0.01). Rats that were fed the high-fat diet presented severe insulin resistance, indicated by a low K itt (p<0.01). Interestingly, the HF81 rats exhibited greater insulin resistance compared with the HF120 rats (p<0.05). The recordings of vagus nerve activity showed that the HF rats had higher parasympathetic activity than the NF rats irrespective of age (p<0.01). Our results show that a high-fat diet offered to rats just after weaning or in adulthood both cause impairment of glycemic homeostasis and imbalance in parasympathetic activity. Importantly, the consumption of high-fat diet immediately after weaning has more drastic consequences compared with the consumption of the same diet during adulthood.
authors.affiliation: Department of Cell Biology and Genetics, Laboratory of Secretion Cell Biology, State University of Maringá, Maringá, Paraná, Brazil.
authors.forename: L F
authors.initials: LF
authors.lastname: Barella
authors.forename: J C
authors.initials: JC
authors.lastname: de Oliveira
authors.forename: R C S
authors.initials: RC
authors.lastname: Branco
authors.forename: R L
authors.initials: RL
authors.lastname: Camargo
authors.forename: R M
authors.initials: RM
authors.lastname: Gomes
authors.forename: F C V
authors.initials: FC
authors.lastname: Mendes
authors.forename: R A
authors.initials: RA
authors.lastname: Miranda
authors.forename: C
authors.initials: C
authors.lastname: Gravena
authors.forename: R
authors.initials: R
authors.lastname: Torrezan
authors.forename: S
authors.initials: S
authors.lastname: Grassiolli
authors.forename: P C
authors.initials: PC
authors.lastname: de Freitas Mathias
mesh_terms: D000273:Adipose Tissue / Q000187:drug effects; D000375:Aging / Q000187:drug effects / Q000378:metabolism*; D000818:Animals; D001786:Blood Glucose / Q000187:drug effects / Q000378:metabolism; D059305:Diet, High-Fat / Q000009:adverse effects*; D055724:Electrophysiological Phenomena / Q000187:drug effects; D005247:Feeding Behavior / Q000187:drug effects; D005951:Glucose Tolerance Test; D006706:Homeostasis / Q000187:drug effects; D007328:Insulin / Q000097:blood / Q000494:pharmacology; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D014630:Vagus Nerve / Q000187:drug effects / Q000502:physiology
chemical_list: D001786:Blood Glucose; D007328:Insulin