School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol BS8 1TD, UK.
Institute of Molecular Biology, University of Mainz, Mainz 55122, Germany.
Endocrinology. 2024 Feb 20;165(4). doi: 10.1210/endocr/bqae020.
A series of well-described anabolic and catabolic neuropeptides are known to provide short-term, homeostatic control of energy balance. The mechanisms that govern long-term, rheostatic control of regulated changes in energy balance are less well characterized. Using the robust and repeatable seasonal changes in body mass observed in Siberian hamsters, this report examined the role of prolactin in providing long-term rheostatic control of body mass and photoinduced changes in organ mass (ie, kidney, brown adipose tissue, uterine, and spleen). Endogenous circannual interval timing was observed after 4 months in a short photoperiod, indicated by a significant increase in body mass and prolactin mRNA expression in the pituitary gland. There was an inverse relationship between body mass and the expression of somatostatin (Sst) and cocaine- and amphetamine-regulated transcript (Cart). Pharmacological inhibition of prolactin release (via bromocriptine injection), reduced body mass of animals maintained in long photoperiods to winter-short photoperiod levels and was associated with a significant increase in hypothalamic Cart expression. Administration of ovine prolactin significantly increased body mass 24 hours after a single injection and the effect persisted after 3 consecutive daily injections. The data indicate that prolactin has pleiotropic effects on homeostatic sensors of energy balance (ie, Cart) and physiological effectors (ie, kidney, BAT). We propose that prolactin release from the pituitary gland acts as an output signal of the hypothalamic rheostat controller to regulate adaptive changes in body mass.
已知一系列描述良好的合成代谢和分解代谢神经肽可提供短期的能量平衡稳态控制。调节能量平衡的长期、变阻控制的机制尚未得到很好的描述。本报告利用西伯利亚仓鼠体内观察到的健壮且可重复的季节性体重变化，研究了催乳素在提供体重的长期变阻控制和光诱导的器官质量变化（即肾脏、棕色脂肪组织、子宫和脾脏）中的作用。在短光照周期中观察到内源性的年际间隔计时，这表现为垂体中体重和催乳素 mRNA 表达显著增加。体重与生长抑素 (Sst) 和可卡因-安非他命调节转录物 (Cart) 的表达呈负相关。催乳素释放的药理学抑制（通过溴隐亭注射）将长期光照条件下饲养的动物的体重降低到冬季短光照条件下，并与下丘脑 Cart 表达的显著增加相关。单次注射绵羊催乳素后 24 小时内显著增加体重，连续 3 天注射后效果持续。数据表明，催乳素对能量平衡的稳态传感器（即 Cart）和生理效应器（即肾脏、BAT）具有多种作用。我们提出，垂体催乳素的释放作为下丘脑变阻控制器的输出信号，调节体重的适应性变化。
