Kyrkouli S E, Stanley B G, Leibowitz S F
Rockefeller University, New York, NY 10021.
Life Sci. 1992;51(3):203-10. doi: 10.1016/0024-3205(92)90076-2.
Evidence suggests that the peptides galanin (GAL) and neuropeptide Y (NPY) interact with the amine norepinephrine (NE) in the hypothalamic paraventricular nucleus (PVN) to stimulate feeding behavior. To directly investigate the nature of these interactions, extracellular levels of PVN NE were monitored in freely-moving rats using the microdialysis/HPLC technique. Following PVN administration of GAL (0.3 nmol), NPY (78 pmol) or Ringer's solution, local NE levels were measured at 20-min intervals for 2 hrs postinjection, under two feeding conditions, namely, in the presence or absence of food. The results demonstrate different effects of these peptides on endogenous NE levels. Following GAL administration, PVN NE levels were enhanced by 80 to 90%, up to 40 min postinjection, independent of food availability. In contrast, following NPY injection, NE levels were significantly reduced 20 min postinjection with food absent, and when food was available, NE levels tended to be enhanced. These results, consistent with pharmacological and biochemical studies, reveal different patterns of peptide-amine interactions in the PVN.
有证据表明，肽类物质甘丙肽（GAL）和神经肽Y（NPY）在下丘脑室旁核（PVN）中与胺类去甲肾上腺素（NE）相互作用，以刺激进食行为。为了直接研究这些相互作用的本质，使用微透析/高效液相色谱技术在自由活动的大鼠中监测PVN中NE的细胞外水平。在PVN注射GAL（0.3 nmol）、NPY（78 pmol）或林格氏液后，在两种进食条件下，即在有食物或无食物的情况下，注射后2小时内每隔20分钟测量一次局部NE水平。结果表明这些肽对内源性NE水平有不同影响。注射GAL后，PVN中NE水平在注射后40分钟内提高了80%至90%，与食物供应情况无关。相比之下，注射NPY后，在无食物时注射后20分钟NE水平显著降低，而在有食物时，NE水平则趋于升高。这些结果与药理学和生化研究一致，揭示了PVN中肽-胺相互作用的不同模式。
