Effects of maternal separation stress on glucose homeostasis in pubertal male rats

Exposure to stress in postnatal period of life increases the risk of metabolic, behavioral and psychological disorders in later life. In this regard, the present study investigated the effects of maternal separation stress on plasma glucose and insulin concentrations and HOMA-IR (Homeostasis model assessment of insulin resistance) index, in male rats at puberty.
After birth, the animals were divided into "stress” and “non-stress " groups. The stressed rats were separated from their mothers at postnatal days (PND 1 to 21, 3h/day), whereas non-stressed rats remained with their mothers. At puberty (day 53), the animals were decapitated and their blood samples collected to measure plasma concentrations of insulin, glucose and corticosterone. Moreover, HOMA-IR index was calculated.
Maternal separation stress increased plasma glucose concentration in adult male rats, but did not significantly affect plasma insulin concentration. Notably, the HOMA-IR index in stressed rats showed a significant increase. Meanwhile, in the animals of this group, basal plasma corticosterone levels increased significantly compared to non-stressed animals.
This study shows that maternal separation during infancy period, possibly, through changes in HPA axis programming induces insulin resistance and impairs glucose homeostasis in puberty and these changes may predispose the rats to metabolic disorders