Holmes L J, Storlien L H, Smythe G A
Garvan Institute of Medical Research, St. Vincent's Hospital, Darlinghurst, New South Wales, Australia.
Am J Physiol. 1989 Feb;256(2 Pt 1):E236-41. doi: 10.1152/ajpendo.1989.256.2.E236.
This study elucidated the hypothalamic monoamine systems associated with the cephalic phase insulin release. Male Wistar rats conditioned to drink a glucose solution were killed 2 min after the onset of their scheduled feeding; control rats were killed at the same time. The ventromedial (VMH) and lateral (LH) portions of the hypothalamus were analyzed for the monoamines and their principal metabolites. Serum was assayed for insulin and glucose. The results showed that the experimental animals had significantly higher serum insulin levels than did the control animals, although glucose levels were unchanged. In the LH, there were increased levels of norepinephrine, its metabolite dihydroxyphenylethylene glycol (DHPG), and serotonin [(5-hydroxytryptamine (5-HT)]. In the VMH, 5-HT, its metabolite 5-hydroxyindoleacetic acid, and the dopamine metabolite 3,4-dihydroxyphenylacetic acid (DOPAC) were all higher in the conditioned animals. 5-HT levels in the LH and DOPAC levels in the VMH were closely associated with serum insulin (r = 0.80 and 0.71, respectively). This study has defined, in the normal animal, changes in monoamines in specific areas of the hypothalamus associated with the cephalic phase insulin release.
本研究阐明了与头期胰岛素释放相关的下丘脑单胺系统。对适应饮用葡萄糖溶液的雄性Wistar大鼠，在其预定进食开始2分钟后处死；同时处死对照大鼠。分析下丘脑腹内侧核（VMH）和外侧核（LH）中的单胺及其主要代谢产物。检测血清中的胰岛素和葡萄糖。结果显示，尽管葡萄糖水平未变，但实验动物的血清胰岛素水平显著高于对照动物。在LH中，去甲肾上腺素、其代谢产物二羟苯乙二醇（DHPG）和血清素[5-羟色胺（5-HT）]水平升高。在VMH中，条件动物的5-HT、其代谢产物5-羟吲哚乙酸以及多巴胺代谢产物3,4-二羟基苯乙酸（DOPAC）均升高。LH中的5-HT水平和VMH中的DOPAC水平与血清胰岛素密切相关（r分别为0.80和0.71）。本研究确定了在正常动物中，下丘脑特定区域与头期胰岛素释放相关的单胺变化。
