Parra-Montes de Oca Marco Antonio, Gutiérrez-Mariscal Mariana, Salmerón-Jiménez Ma Félix, Jaimes-Hoy Lorraine, Charli Jean-Louis, Joseph-Bravo Patricia
Departamento de Genética del Desarrollo y Fisiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de Mexico, Cuernavaca, Mexico.
Front Endocrinol (Lausanne). 2019 Jun 26;10:418. doi: 10.3389/fendo.2019.00418. eCollection 2019.
The activity of the hypothalamus-pituitary-thyroid (HPT) axis is inhibited by energy deficit, by acute or chronic stress, but activated by cold exposure or exercise. Because stress curtails acute cold induced activation of HPT, we evaluated the effect of chronic stress on HPT axis response to voluntary exercise, a persistent energy-demanding situation. Adult male and female Wistar rats were exposed to restraint stress, 30 min/day for 2 weeks, or to isolation (Iso) [post-natal day [PND] 30-63]. Exercise was performed (7 p.m.-7 a.m.) in a running wheel, sedentary controls stayed in individual cages (Sed); at 7 a.m. they were housed with their cage mate or individually (Iso); food intake by the exercised group was measured day and night to pair-fed Sed. At sacrifice, hormones, mRNA levels and tissue weights were quantified. Control or restrained adult rats had access to running wheel daily for 2 weeks. Compared to C, exercise decreased white adipose tissue (WAT) mass in females and males, increased hypothalamic paraventricular nucleus (PVN)- expression in males proportionally to exercise performed, and increased TSH and T4 serum concentration in females. These changes were not detected in restrained groups. Starting at PND 63 control (2/cage) and isolated (1/cage) rats either exercised on 10 alternated nights or were sedentary. In control male animals, compared to Sed rats, exercise did not decrease WAT mass, nor changed HPT axis activity, but increased and deiodinase 2 () expression in mediobasal hypothalamus (MBH), adrenergic receptor β3 and uncoupling protein-1 in brown adipose tissue. In control female animals, exercise decreased WAT mass, increased , and expression in MBH, and TSH serum concentration. Iso females had lower TSH and T4 serum concentration, and expression in MBH than controls. The stress response was higher in isolated males than females, but in males it did not alter the effects of exercise, in contrast to isolated females that had a blunted response to exercise compared to controls. In conclusion, chronic stress interferes with metabolic effects produced by exercise, such as loss of WAT mass, coincident with dampening of HPT activity.
下丘脑 - 垂体 - 甲状腺（HPT）轴的活性会受到能量缺乏、急性或慢性应激的抑制，但会因冷暴露或运动而被激活。由于应激会削弱急性寒冷诱导的HPT激活，我们评估了慢性应激对HPT轴对自愿运动（一种持续的能量需求情况）反应的影响。成年雄性和雌性Wistar大鼠分别接受束缚应激（每天30分钟，持续2周）或隔离（出生后第30 - 63天）。运动在跑步轮中进行（晚上7点至早上7点），久坐对照组留在单独的笼子里（Sed）；早上7点时，它们与同笼伙伴一起饲养或单独饲养（隔离）；测量运动组的昼夜食物摄入量，以便对Sed组进行配对喂养。处死时，对激素、mRNA水平和组织重量进行定量。对照或束缚成年大鼠每天可使用跑步轮2周。与对照组相比，运动可降低雌性和雄性大鼠的白色脂肪组织（WAT）质量，雄性大鼠下丘脑室旁核（PVN）的表达随运动量成比例增加，雌性大鼠血清促甲状腺激素（TSH）和甲状腺素（T4）浓度升高。在束缚组中未检测到这些变化。从出生后第63天开始，对照（每笼2只）和隔离（每笼1只）大鼠要么在10个交替的夜晚进行运动，要么久坐不动。在对照雄性动物中，与Sed大鼠相比，运动并未降低WAT质量，也未改变HPT轴活性，但增加了中基底下丘脑（MBH）中的解偶联蛋白2（UCP2）和脱碘酶2（DIO2）表达、棕色脂肪组织中的肾上腺素能受体β3和解偶联蛋白 - 1。在对照雌性动物中，运动降低了WAT质量，增加了MBH中的UCP2、DIO2表达和血清TSH浓度。隔离的雌性大鼠血清TSH和T4浓度、MBH中的UCP2和DIO2表达均低于对照组。隔离雄性大鼠的应激反应高于雌性，但与隔离雌性大鼠相比，雄性大鼠的应激反应并未改变运动的效果，隔离雌性大鼠与对照组相比对运动的反应减弱。总之，慢性应激会干扰运动产生的代谢效应，如WAT质量的减少，同时伴随着HPT活性的减弱。
