The thyroid axis, prolactin, and exercise in humans

Abstract

The thyroid hormones thyroxine and triiodothyronine as well as the anterior pituitary hormone prolactin each serve vital roles in humans. When challenged by stressful situations, all of these hormones respond in an attempt to maintain homeostasis. One powerful stressor to invoke the release of these hormones is physical activity, that is, exercise. The thyroids and prolactin each have independent roles allowing the body to accommodate to exercise. But they also share an interrelation in their responses. Hypothalamic thyrotropin-releasing hormone release invoked by stress stimulates the release of thyroid-stimulating hormone and thus the thyroids as well as the release of prolactin. Likewise, estrogen serves as an interconnective regulatory link by stimulating the release of both the thyroids and prolactin. The roles of these hormones in exercise are multifaceted, but one overlapping and common function is their combined aid and support of the tissue inflammatory responses after exercise. This is highly critical for facilitating elements of the adaptive-recovery procedures to exercise and exercise training.

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

“…The effect of exercise on HPT axis activity in humans varies with its duration; the increase of serum TSH, T4 and T3 concentrations during exercise are reverted during recovery ( 127 ). Depending on health state and physical condition, the response of HPT axis to exercise differs between men and women.…”

Genome-wide association studies of 27 accelerometry-derived physical activity measurements identified novel loci and genetic mechanisms

“…Interestingly, three TWAS loci that were significant in digestive tissues were associated with PA phenotypes that are proxies for meal-time activity: PDXDC2P with TLA 6am-8am, RERE with TLA 6pm-8PM and KANSL1 with TLA 4pm-6pm ( Table 2 ). It was also known that multiple organs in the endocrine system produce hormones that regulate physiological functions of the body, which can have complex bidirectional relationships with PA 39–43 . Our TWAS analysis indicated that the genes associated with PA via the blood and immune system tended to also be associated with the digestive and endocrine systems, but do not usually overlap with the genes associated with the CNS.…”

Effects of physical activity on prolactin and thyroid hormones

“…Регуляция всех этих гормонов осуществляется согласно ме-ханизму отрицательной обратной связи в оси гипоталамус -гипофиз -щитовидная железа [20]. Факторы, оказывающие стимулирующее или подавляющее влияние на компоненты этой оси, представлены в таблице 1 [21].…”