title: Sex-specific effects of isolation stress and consumption of palatable diet during the prepubertal period on metabolic parameters.
abstract: OBJECTIVE
  Social isolation during the prepubertal period may have long-term effects on metabolism. The exposure to stressful events is associated with increased palatable food intake, constituting reward-based eating. However, palatable food consumption in early life may lead to metabolic alterations later in life. We investigated whether isolation stress during early life can lead to metabolic alterations in male and female rats with or without exposure to a palatable diet.
  
  
  METHODS
  Animals were stressed by isolation during one week after weaning, with or without exposure to a palatable diet.
  
  
  RESULTS
  Stress and palatable diet induced increased caloric consumption. In females, there was a potentiation of consumption in animals exposed to stress and palatable diet, reflected by increased weight gain and triacylglycerol levels in juveniles, as well as increased adiponectin levels. Most of the effects had disappeared in the adults. Different effects were observed in males: in juveniles, stress increased unacylated ghrelin levels, and hypothalamic neuropeptide Y (NPY). Subsequently, adult males that were exposed to a palatable diet during prepuberty showed increased body weight and retroperitoneal fat deposition, increased glycemia, and decreased plasma adiponectin and hypothalamic NPY. Exposure to stress during prepuberty led to increased adrenals during adulthood, decreased LDL-cholesterol and increased triacylglycerol levels.
  
  
  CONCLUSIONS
  Isolation stress and consumption of palatable diet changes metabolism in a sex-specific manner. Prepuberty female rats were more prone to stress effects on food consumption, while males showed more long-lasting effects, being more susceptible to a metabolic programming after the consumption of a palatable diet.
authors.affiliation: Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, UFRGS, Porto Alegre, Rio Grande do Sul, Brazil. krolowrachel@yahoo.com.br
authors.forename: Rachel
authors.initials: R
authors.lastname: Krolow
authors.forename: Cristie
authors.initials: C
authors.lastname: Noschang
authors.forename: Danusa M
authors.initials: DM
authors.lastname: Arcego
authors.forename: Ana P
authors.initials: AP
authors.lastname: Huffell
authors.forename: Marina L
authors.initials: ML
authors.lastname: Marcolin
authors.forename: André N
authors.initials: AN
authors.lastname: Benitz
authors.forename: Carine
authors.initials: C
authors.lastname: Lampert
authors.forename: Raquel D
authors.initials: RD
authors.lastname: Fitarelli
authors.forename: Carla
authors.initials: C
authors.lastname: Dalmaz
mesh_terms: D052242:Adiponectin / Q000097:blood; D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D004435:Eating; D005260:Female; D007031:Hypothalamus / Q000737:chemistry; D007328:Insulin / Q000097:blood; D008297:Male; D009478:Neuropeptide Y / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D012727:Sex Characteristics; D012741:Sexual Maturation / Q000502:physiology*; D012934:Social Isolation; D013315:Stress, Psychological / Q000378:metabolism*; D015430:Weight Gain
chemical_list: D052242:Adiponectin; D001786:Blood Glucose; D007328:Insulin; D009478:Neuropeptide Y
keywords: Abdominal fat; Adiponectin; EDTA; Ethylenediamine tetraacetic acid; GCs; Ghrelin; HDL; HPA; Insulin; LDL; NPY; PND; Social stress; Sweet food; VLDL; glucocorticoids; high-density lipoprotein; hypothalamic neuropeptide Y; hypothalamo-pituitary adrenal axis; low-density lipoprotein; postnatal day; very low density lipoprotein