Decreased Intake of Sucrose Solutions in Orexin Knockout Mice
Decreased Intake of Sucrose Solutions in Orexin Knockout Mice
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DOI：
10.1007/s12031-010-9475-1
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发表时间：
2011-02-01
影响因子：
3.1
通讯作者：
Inoue, Tomio
中科院分区：
文献类型：
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作者：
Matsuo, Eiko;Mochizuki, Ayako;Inoue, Tomio
食欲素由外侧下丘脑神经元合成，并被认为与摄食行为有关。最近的研究表明，在脑室内给予食欲素- a会增加甜味溶液的摄入量。然而，抑制食欲素系统对甜味溶液的消耗和甜味输入的感官加工的影响尚未得到研究。我们研究了食欲素缺乏对蔗糖溶液摄入、运动活动和对甜味溶液偏好的影响，使用雄性食欲素敲除（OxKO）和同窝野生型（WT）小鼠。在黑暗和24小时内，与WT小鼠相比，OxKO小鼠在食物摄入没有改变的情况下，蔗糖摄入量明显减少，运动活性降低，而对100毫米蔗糖的偏好在基因型之间没有差异。此外，与OxKO小鼠相比，OxKO小鼠的蔗糖摄入量显著低于运动活动相似的WT小鼠亚组的蔗糖摄入量。这些结果表明，除了运动活动减少导致的能量消耗减少之外，其他因素可能是导致OxKO小鼠蔗糖摄入量减少的原因。食欲素缺乏可能降低饱腹感阈值，导致蔗糖摄入量减少，而不改变食物摄入量。
Orexins are synthesized by lateral hypothalamic neurons and are suggested to be implicated in feeding behavior. Recent studies have shown that intracerebroventricular administration of orexin-A increases intake of sweet-tasting solution. Effects of suppressing the orexin system on consumption of sweet-tasting solution and sensory processing with sweet taste inputs, however, have yet to be examined. We examined the effects of orexin deficiency on sucrose solution intake, locomotor activity, and preference for sweet solution using male orexin knockout (OxKO) and littermate wild-type (WT) mice. In the dark and over 24-h periods, OxKO mice showed significantly less sucrose intake and lower locomotor activity than WT mice without alteration in food intake whereas preferences for 100 mM sucrose were not different between the genotypes. Moreover, sucrose intake of OxKO mice was significantly less than sucrose intake of a subgroup of WT mice with similar locomotor activity compared to that of OxKO mice. These results suggest that factors other than the lower energy expenditure due to lower locomotor activity are likely responsible for the decreased sucrose intake of OxKO mice. Orexin deficiency may lower the satiety threshold resulting in reduced sucrose intake, without altering food intake.