Menéndez J A, McGregor I S, Healey P A, Atrens D M, Leibowitz S F
Department of Psychology, University of Sydney, N.S.W., Australia.
Brain Res. 1990 May 14;516(1):8-14. doi: 10.1016/0006-8993(90)90890-n.
The metabolic effects of single injections of neuropeptide Y (NPY) into the paraventricular hypothalamus were investigated in an open-circuit calorimeter. Wistar rats were tested, with no food available during the tests. Over the dose range of 10-156 pmol NPY had large effects on respiratory quotient (RQ) while having no effect on energy expenditure or locomotor activity. The effects of NPY on RQ were unusual both in respect to their dose-response and time-dose-response characteristics. The lowest dose (10 pmol) produced a very low latency reduction in RQ which indicates a decreased utilization of carbohydrates as an energy substrate. The next higher dose (20 pmol) had no effect, whereas the next three doses (39, 78 and 156 pmol) produced increases in RQ which indicate an increased utilization of carbohydrates as an energy substrate. Surprisingly, the latencies of the increased RQs were dose-dependent over the range of 30 min to 20 h with the highest dose producing the longest latency effect. The finding of a positive relation of dose to response latency over a time range of from a few minutes to 20 h is unprecedented and appears to represent a neuromodulatory effect of NPY that acts in concert with its neurotransmitter effects. These data highlight the central role of NPY in modulating energy substrate utilization and indicate the importance of elucidating time-dose-response relationships when investigating the effects of NPY.
在开路式热量计中研究了向室旁下丘脑单次注射神经肽Y（NPY）的代谢效应。使用Wistar大鼠进行测试，测试期间不提供食物。在10 - 156皮摩尔的剂量范围内，NPY对呼吸商（RQ）有很大影响，而对能量消耗或运动活动没有影响。NPY对RQ的影响在剂量反应和时间 - 剂量反应特征方面都很不寻常。最低剂量（10皮摩尔）使RQ出现非常低延迟的降低，这表明作为能量底物的碳水化合物利用率降低。次高剂量（20皮摩尔）没有影响，而接下来的三个剂量（39、78和156皮摩尔）使RQ增加，这表明作为能量底物的碳水化合物利用率增加。令人惊讶的是，在30分钟至20小时的范围内，RQ增加的延迟与剂量相关，最高剂量产生最长延迟效应。在几分钟到20小时的时间范围内发现剂量与反应延迟呈正相关是前所未有的，这似乎代表了NPY的一种神经调节作用，它与其神经递质作用协同发挥作用。这些数据突出了NPY在调节能量底物利用中的核心作用，并表明在研究NPY的作用时阐明时间 - 剂量反应关系的重要性。
