Long-Term Effects of Stress During Adolescence on the Sex-Dependent Responses of Thyroid Axis and Target Tissues to Exercise in Male and Female Wistar Rats

The response of the hypothalamic-pituitary-thyroid (HPT) axis to energy demands is perturbed by previous chronic stress perceived during the neonatal or adult periods. We examined the effects of chronic variable stress (CVS) during adolescence on the responses of the HPT axis and target tissues of adult rats to 14 days of voluntary wheel running (Ex) or pair-feeding (PF) to match the reduced food intake of exercised rats. CVS increased the expression of <i>Gr</i> in the paraventricular nucleus (PVN) and of <i>Npy</i> in the mediobasal hypothalamus (MBH) in males; serum corticosterone concentration increased (1.5×), MBH <i>Dio2</i> and PVN <i>Trh</i> decreased (40%) in both sexes, serum fT4 increased only in males, while T3 and fT3 increased (2×) in females. Exercise decreased Cort and increased PVN <i>Trh</i> expression only in males. In both sexes, it increased MBH <i>Pomc</i> and <i>Dio2</i> (2×), skeletal muscle <i>Dio2</i> and <i>Pgc1a</i> (2×), inguinal and perigonadal white adipose tissue (WAT) <i>Adrb3</i>, <i>Dio2</i>, <i>Pparg</i>, <i>Hsl</i> (1.5×), and brown adipose tissue <i>Adrb3</i>, <i>Dio2</i>, and <i>Ucp1</i>. All exercise-induced changes were repressed in CVS-Ex, except <i>Hsl</i> in inguinal WAT of both sexes, or BAT <i>Dio2</i> in females, which, in contrast, was stimulated (1.5×). PF had lower values than sedentary in most parameters. These results support the idea that adolescent stress affects adult metabolic and neuroendocrine responses to exercise in a sex-specific manner.