Enhanced initial and sustained intake of sucrose solution in mice with an oxytocin gene deletion
Enhanced initial and sustained intake of sucrose solution in mice with an oxytocin gene deletion
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DOI：
10.1152/ajpregu.00558.2005
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发表时间：
2005-12-01
影响因子：
2.8
通讯作者：
Rinaman, L
中科院分区：
文献类型：
--
作者：
Amico, JA;Vollmer, RR;Rinaman, L
实验室老鼠在最初接触蔗糖溶液时喝得很少，但后来对蔗糖产生了强烈的偏好，几天后这种偏好趋于稳定。最初的新恐惧症和后来的蔗糖摄入平台可能涉及中枢催产素（OT）信号通路。如果是这样，那么与野生型（WT）相比，缺乏OT基因（KO）的小鼠应该表现出更高的初始和持续蔗糖摄入量。为了验证这一假设，雌性OT - KO和WT小鼠（11-13月龄）被给予两瓶10%蔗糖和水的自由选择，为期4天。在第一天，与WT组相比，OT KO小鼠的蔗糖摄入量增加了20倍。在第2天，OT - KO小鼠的糖摄取量进一步增加，且持续显著高于WT小鼠的摄取量。在5- 7岁的雄性OT - KO小鼠中也观察到初始和持续的蔗糖摄入量增加。基因型的影响在一定的蔗糖浓度范围内观察到，并在至少8天的持续暴露中保持不变。然而，基因型对日摄食量无显著影响。这些发现表明，小鼠体内OT的遗传缺失与初始和持续摄入蔗糖溶液的增强有关。因此，中枢OT通路通常可能参与限制新食材的初始摄入，也可能参与限制甜的、非常美味的熟悉食材的摄入。
Laboratory mice drink little sucrose solution on initial exposure, but later develop a strong preference for sucrose over water that plateaus after a few days. Both the initial neophobia and later plateau of sucrose intake may involve central oxytocin (OT) signaling pathways. If so, then mice that lack the gene for OT [OT knockout ( KO)] should exhibit enhanced initial and sustained sucrose intake compared with wild-type (WT) cohorts. To test this hypothesis, female OT KO and WT mice (11-13 mo old) were given a two-bottle choice between 10% sucrose and water available ad libitum for 4 days. On the first day, sucrose intake was 20-fold greater in OT KO mice compared with WT cohorts. The avid sucrose consumption by OT KO mice increased further on day 2 and was sustained at significantly higher levels than intake by WT mice. Enhanced initial and sustained sucrose intake also was observed in 5- to 7-mo-old male OT KO mice. The effect of genotype was observed over a range of sucrose concentrations and was maintained over at least 8 days of continual exposure. However, there was no effect of genotype on daily intake of sucroseenriched powdered chow. These findings indicate that the genetic absence of OT in mice is associated with enhanced initial and sustained intake of sucrose solutions. Thus central OT pathways may normally participate in limiting initial intake of novel ingesta and may also participate in limiting intake of sweet, highly palatable familiar ingesta.