Toth Istvan, Kiss David S, Jocsak Gergely, Somogyi Virag, Toronyi Eva, Bartha Tibor, Frenyo Laszlo V, Horvath Tamas L, Zsarnovszky Attila
Department of Physiology and Biochemistry, Szent Istvan University Faculty of Veterinary Science, Budapest, Hungary.
Department of Transplantation and Surgery, Semmelweis University, Budapest, Hungary.
PLoS One. 2015 Sep 4;10(9):e0137462. doi: 10.1371/journal.pone.0137462. eCollection 2015.
Hypothalamus is the highest center and the main crossroad of numerous homeostatic regulatory pathways including reproduction and energy metabolism. Previous reports indicate that some of these functions may be driven by the synchronized but distinct functioning of the left and right hypothalamic sides. However, the nature of interplay between the hemispheres with regard to distinct hypothalamic functions is still unclear. Here we investigated the metabolic asymmetry between the left and right hypothalamic sides of ovariectomized female rats by measuring mitochondrial respiration rates, a parameter that reflects the intensity of cell and tissue metabolism. Ovariectomized (saline injected) and ovariectomized+estrogen injected animals were fed ad libitum or fasted to determine 1) the contribution of estrogen to metabolic asymmetry of hypothalamus; and 2) whether the hypothalamic asymmetry is modulated by the satiety state. Results show that estrogen-priming significantly increased both the proportion of animals with detected hypothalamic lateralization and the degree of metabolic difference between the hypothalamic sides causing a right-sided dominance during state 3 mitochondrial respiration (St3) in ad libitum fed animals. After 24 hours of fasting, lateralization in St3 values was clearly maintained; however, instead of the observed right-sided dominance that was detected in ad libitum fed animals here appeared in form of either right- or left-sidedness. In conclusion, our results revealed estrogen- and satiety state-dependent metabolic differences between the two hypothalamic hemispheres in female rats showing that the hypothalamic hemispheres drive the reproductive and satiety state related functions in an asymmetric manner.
下丘脑是最高中枢，也是包括生殖和能量代谢在内的众多稳态调节途径的主要交叉点。先前的报告表明，其中一些功能可能由左右下丘脑侧同步但不同的功能驱动。然而，关于不同下丘脑功能的半球间相互作用的本质仍不清楚。在这里，我们通过测量线粒体呼吸速率来研究去卵巢雌性大鼠左右下丘脑侧之间的代谢不对称性，线粒体呼吸速率是反映细胞和组织代谢强度的一个参数。对去卵巢（注射生理盐水）和去卵巢+注射雌激素的动物进行自由进食或禁食，以确定1）雌激素对下丘脑代谢不对称性的作用；以及2）下丘脑不对称性是否受饱腹感状态的调节。结果表明，雌激素预处理显著增加了检测到下丘脑侧化的动物比例以及下丘脑两侧之间的代谢差异程度，在自由进食的动物中，导致在状态3线粒体呼吸（St3）期间右侧占优势。禁食24小时后，St3值的侧化明显维持；然而，与自由进食动物中观察到的右侧优势不同，这里出现了右侧或左侧优势的形式。总之，我们的结果揭示了雌性大鼠两个下丘脑半球之间雌激素和饱腹感状态依赖性的代谢差异，表明下丘脑半球以不对称的方式驱动与生殖和饱腹感状态相关的功能。
