High-Fat Feeding Influences the Endocrine Responses of Pubertal Rats to an Acute Stress

Abstract

Background/Aims: Studies conducted in adult rats have shown that increased fat intake affects brain energy homeostasis and stress response. The neuroendocrine circuits controlling the aforementioned functions continue to mature during puberty. The aim of the present study was to investigate whether post-weaning high-fat consumption can modify the endocrine responses of pubertal rats to an acute stress. Methods: Weaning male and female Wistar rats on postnatal day (P) 22 were fed either a high-fat (HF; 45% calories from fat) or a control (10% calories from fat) diet and were sacrificed on the individual day of puberty onset (between P35 and P42) under basal conditions or 4 h after swimming stress. Plasma insulin, leptin and corticosterone levels were determined by radioimmunoassay and the respective receptors in the hypothalamus and hippocampus were determined by Western blot analysis. Results: Stressed HF-fed males showed a smaller increase in plasma insulin levels than chow-fed males. Their leptin receptor levels were reduced in the hypothalamus, but not in the hippocampus, and their glucocorticoid receptor levels were increased in the hypothalamus compared to stressed chow-fed males. HF-fed females were nonresponsive to stress-induced alterations in plasma glucose and corticosterone levels, as well as to hippocampal insulin receptors following stress. Several sex differences were also revealed in the endocrine responses of HF-fed animals following stress. Conclusions: These data show that consumption of high-fat foods during preadolescence can modify the endocrine responses to an acute stress by affecting both stress and metabolic mediators in a sexually dimorphic manner.

Gender-dependent resiliency to stressful and metabolic challenges following prenatal exposure to high-fat diet in the p66Shc−/− mouse

“…These results are apparently not in line with some previous studies showing that HFD exposure during pregnancy and/or the early postnatal period advances puberty onset in female rats (Boukouvalas et al, 2008, 2010; Chang et al, 2008; Sloboda et al, 2009; Akamine et al, 2010; Li et al, 2012). Such discrepancy may be due to the fact that percent of fat content has been suggested to be critical for the quality of the effects produced by the diet (Chang et al, 2008; Moral et al, 2011; Lie et al, 2013).…”

Highly Palatable Food during Adolescence Improves Anxiety-Like Behaviors and Hypothalamic-Pituitary-Adrenal Axis Dysfunction in Rats that Experienced Neonatal Maternal Separation

“…Studies comparing HPA axis activity in prepubertal and adult rats show that there is a significantly persistent hormonal stress response in prepubertal animals compared to adults [35,36,37]. Previous study suggested that a postweaning highly preferred diet can modify the basal HPA axis activity and the endocrine responses to an acute stress by affecting both stress and metabolic mediators [38,39]. Exposure to a highly preferred diet high in fat was suggested to reduce stress sensitivity [10].…”

Exposure to Prenatal Psychobiological Stress Exerts Programming Influences on the Mother and Her Fetus

“…There is a rapidly expanding literature in animal models indicating that there are sexually dimorphic responses to stress and adversity [122,123,124] including and perhaps especially associated with stress during the prenatal period [125,126,127]. In the study of human FHR responses to external stimulation reported above [44], we discovered that female fetuses displayed more mature responses than males at 31 and 36 gestational weeks.…”