Chronic stress inhibits hypothalamus–pituitary–thyroid axis and brown adipose tissue responses to acute cold exposure in male rats

Sex Dimorphic Responses of the Hypothalamus-Pituitary-Thyroid Axis to Energy Demands and Stress

“…Chronic stress imposed by individual housing (isolation) for 7 days after weaning increases serum TT4 concentration in female but not in male rats ( 114 ). Chronic variable stress, a model that resembles chronic stress in humans as it produces a constant secretion of glucocorticoids, increases Tshb expression in pituitary of females but not male mice ( 137 ) while in rats, TSH serum concentration decreases in males ( 138 ). This contradiction could stem from the type of stressors applied or to species-differences ( 139 ) and illustrate the difficulty in pointing the causes of sex-differences.…”

“…Not only basal activity of HPT axis is altered by stress, the stress history of the animal also affects HPT axis response to energy demands. Albeit not studied yet in females, acute or chronic stress blunts the acute cold-induced stimulation of PVN Trh synthesis, TSH release and BAT activation in male rats ( 6 , 138 ), through a direct effect of corticosterone inhibiting cold-induced CREB phosphorylation in TRHergic neurons ( 140 ). Some types of stress can interfere with the stimulatory effect of voluntary exercise on HPT axis activity and loss of fat mass; male or female rats are similarly affected by two weeks of chronic intermittent restraint but in response to isolation stressed males do not lose fat nor activate any of the variables of the HPT axis whereas females are not affected ( 75 ).…”

“…Our results that stress curtails adequate lipolysis as it impedes exercise-induced fat loss and diminishes running probably due to fatigue, suggest interference with the fast and intermittent activation necessary for TH to exert their metabolic effects needed to supply fuels to oxidative tissues ( 8 , 122 , 123 ). These effects, together with the blunting effect of stress on cold-induced activation of HPT axis that impedes to control body temperature ( 138 ) shown in adult males, may contribute to the symptoms of subclinical hypothyroidism. The susceptibility to stress effects depends on sex, age and type of stress.…”

Research progress on adaptive modifications of the gut microflora and regulation of host glucose and lipid metabolism by cold stimulation

“…The results showed that in BAT compared with in WAT the gene expression associated with lipid metabolism in cold induction was up-regulated, and fat mobilization as well as lipid oxidation was accelerated [85] . In cold stress, the function of thermogenic tissues including BAT are influenced by sympathetic and thyroid hormones, therefore the glucose and lipid metabolisms of BAT are regulated in synergy with the hypothalamic-pituitary-thyroid axis (HPT axis) [86] .…”