Gietzen D W, Leung P M, Rogers Q R
Department of Physiological Sciences, School of Veterinary Medicine, University of California, Davis 95616.
Physiol Behav. 1989 Sep;46(3):503-11. doi: 10.1016/0031-9384(89)90028-0.
The impact of feeding imbalanced amino acid diets on monoamine, metabolite and amino acid concentrations was measured in the ventromedial hypothalamus (VMH), lateral hypothalamus (LH) and paraventricular nucleus (PVN). After rats were fed either an isoleucine imbalanced diet, a threonine imbalanced diet, or the appropriate basal or corrected control diets, regional differences were found in neurochemical concentrations. Contrary to our expectations, the limiting amino acid was unchanged in the imbalanced groups, tending to be decreased only in the isoleucine imbalanced-diet group in the PVN. This is the first report that the limiting amino acid was not reduced uniformly in the brain after imbalanced amino acid feeding. In the VMH, norepinephrine (NE) was increased by 22% and 63% in the threonine and isoleucine imbalanced-diet groups, respectively. Since the concentration of NE was affected even before the decrease in feeding, both in the VMH, and, as previously reported, in the prepyriform cortex, the NE system may be involved in very early responses to imbalanced amino acid diets.
在腹内侧下丘脑（VMH）、外侧下丘脑（LH）和室旁核（PVN）中测量了饲喂氨基酸不平衡日粮对单胺、代谢物和氨基酸浓度的影响。在大鼠分别饲喂异亮氨酸不平衡日粮、苏氨酸不平衡日粮或适当的基础日粮或校正对照日粮后，发现神经化学物质浓度存在区域差异。与我们的预期相反，不平衡组中的限制性氨基酸没有变化，仅在PVN的异亮氨酸不平衡日粮组中有降低的趋势。这是首篇关于饲喂氨基酸不平衡日粮后大脑中限制性氨基酸并非均匀减少的报道。在VMH中，苏氨酸和异亮氨酸不平衡日粮组中的去甲肾上腺素（NE）分别增加了22%和63%。由于在摄食量减少之前，VMH以及如先前报道的梨状前皮质中的NE浓度就受到了影响，因此NE系统可能参与了对氨基酸不平衡日粮的早期反应。
