Department of Biology (6931), Radford University, Radford, VA 24142, USA.
Neuropeptides. 2010 Jun;44(3):247-52. doi: 10.1016/j.npep.2009.12.015. Epub 2010 Feb 8.
The central mechanism that mediates litorin-induced satiety is poorly understood, and has not been studied in a non-mammalian species. Therefore, the aim of this study was to determine if litorin-induced satiety in an alternative vertebrate model, the chick, and to elucidate some of the central mechanisms that are associated with this response. In Experiment 1, chicks responded to intracerebroventricular (ICV) injection of litorin with reduced food intake at all doses tested (0.1, 1.0, and 10 nmol), while concurrently, an anti-dipsogenic effect was observed in the two higher doses tested. Whole blood glucose concentrations were not affected. In Experiment 2, chicks that were food-withheld did not reduce their water intake after ICV litorin injection. To determine if litorin affected behaviors unrelated to ingestion, a comprehensive behavior analysis was conducted as Experiment 3. Of the behaviors observed, only the number of feeding pecks was reduced. Other behaviors such as movement, defecation, escape, posture, or deep rest were not affected. Lastly, in Experiment 4, litorin-treated chicks had an increased number of c-Fos immunoreactive cells in the magnocellular division of the paraventricular nucleus. The arcuate nucleus, dorsomedial nucleus, lateral hypothalamus, parvicellular division of the paraventricular nucleus, suprachiasmatic nucleus, periventricular nucleus and the ventromedial hypothalamus were not affected. Therefore, we conclude that ICV litorin causes anorexigenic effects in chicks associated with changes in hypothalamic chemistry that appear to be behavior specific.
目前对于 litorin 诱导饱腹感的中枢机制知之甚少,并且尚未在非哺乳动物物种中进行研究。因此,本研究旨在确定 litorin 是否会在替代的脊椎动物模型——小鸡中引起饱腹感,并阐明与这种反应相关的一些中枢机制。在实验 1 中,小鸡对侧脑室(ICV)注射 litorin 的反应是所有测试剂量(0.1、1.0 和 10 nmol)都减少了食物摄入,同时在两个较高剂量也观察到了抗利尿作用。全血葡萄糖浓度不受影响。在实验 2 中,禁食的小鸡在 ICV litorin 注射后并没有减少水的摄入。为了确定 litorin 是否会影响与摄入无关的行为,进行了实验 3 的全面行为分析。在所观察到的行为中,只有进食啄的次数减少了。其他行为,如运动、排便、逃避、姿势或深度休息不受影响。最后,在实验 4 中,litorin 处理的小鸡在室旁核的大细胞部分中 c-Fos 免疫反应细胞的数量增加。弓状核、背内侧核、外侧下丘脑、室旁核的小细胞部分、视交叉上核、室周核和腹内侧下丘脑不受影响。因此,我们得出结论,ICV litorin 引起小鸡的厌食作用与下丘脑化学变化有关,这些变化似乎是特定于行为的。