Mace Jacob D, Tachibana Tetsuya, Wang Guoqing, Newmyer Brandon A, Guilliams Evin, Gilbert Elizabeth R, Cline Mark A
The Edward Via College of Osteopathic Medicine, Blacksburg, VA, USA.
Department of Agrobiological Science, Faculty of Agriculture, Ehime University, Matsuyama, Japan.
Neuropeptides. 2014 Oct;48(5):305-11. doi: 10.1016/j.npep.2014.06.001. Epub 2014 Jun 24.
Exogenous administration of substance P (SP) exerts anorexigenic effects in both chicks and rats, but the central mechanism mediating this response is poorly understood. Therefore, this study was designed to elucidate mechanisms of SP-induced anorexia using chicks as models. Chicks that received intracerebroventricular (ICV) injections of SP dose-dependably reduced their food intake with no effect on water intake. Next, the diencephalon was isolated from SP-injected chicks and mRNA expression of neuropeptide Y (NPY), corticotropin releasing factor (CRF), urocortin 3 (UCN 3) and CRF receptors were measured but were not affected. When measured in the hypothalamus, mRNA abundance of these and NPY receptors, urotensin 2 (UTS2) and melanocortin receptor 4 (MCR4) were not affected by SP-injection. Quantification of c-Fos immunoreactivity in appetite-associated hypothalamic nuclei demonstrated that the paraventricular nucleus (PVN) was activated in SP-injected chicks. Finally, in the PVN isolated from SP-injected chicks, there was increased expression of UTS2 mRNA while CRF and UCN3 were not affected. Thus, the anorexigenic effects of SP appear to be mediated by PVN activation and may involve UTS2.
外源性给予P物质（SP）对雏鸡和大鼠均有厌食作用，但介导这种反应的中枢机制尚不清楚。因此，本研究以雏鸡为模型，旨在阐明SP诱导厌食的机制。接受脑室内（ICV）注射SP的雏鸡食物摄入量呈剂量依赖性减少，而对水摄入量无影响。接下来，从注射SP的雏鸡中分离出间脑，检测神经肽Y（NPY）、促肾上腺皮质激素释放因子（CRF）、尿皮质素3（UCN 3）和CRF受体的mRNA表达，但未受影响。在下丘脑中检测时，这些物质以及NPY受体、尾加压素2（UTS2）和黑皮质素受体4（MCR4）的mRNA丰度不受SP注射的影响。对与食欲相关的下丘脑核中c-Fos免疫反应性的定量分析表明，注射SP的雏鸡室旁核（PVN）被激活。最后，在从注射SP的雏鸡中分离出的PVN中，UTS2 mRNA表达增加，而CRF和UCN3不受影响。因此，SP的厌食作用似乎是由PVN激活介导的，可能涉及UTS2。
