Taste responses to dilute sucrose solutions are modulated by stage of the estrous cycle and fenfluramine treatment in female rats
Taste responses to dilute sucrose solutions are modulated by stage of the estrous cycle and fenfluramine treatment in female rats
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DOI：
10.1016/j.physbeh.2005.08.001
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发表时间：
2005-10-15
影响因子：
2.9
通讯作者：
Eckel, LA
中科院分区：
文献类型：
--
作者：
Atchley, DPD;Weaver, KL;Eckel, LA
在大鼠卵巢生殖周期的发情期，食量减少。这在一定程度上是通过雌二醇增强负反馈信号抑制进食量的能力来调节的。例如，我们最近报道了芬氟拉明（一种5 -羟色胺激动剂）的厌食作用在发情期间增强。在这里，我们研究了正反馈信号强度的降低，比如那些与食物味道有关的信号，是否有助于在发情大鼠或芬氟拉明治疗后观察到的进餐量的减少。给大鼠短暂接触6种蔗糖溶液（0.0、0.025、0.05、0.1、0.2和0.4 M），并在给药1 mg/kg芬氟拉明或生理盐水的大鼠中监测对这些溶液的平均舔食次数。经生理盐水处理后，发情大鼠对0.025 M蔗糖溶液的舔舐次数少于发情大鼠。在芬氟拉明处理后，仅在发情大鼠中观察到5种蔗糖溶液中3种的舔舐次数减少。这种蔗糖适口性的降低仅限于短暂的接触试验，因为在发情或发情的大鼠中，芬氟拉明并没有降低对0.025 M蔗糖溶液的过夜偏好。我们的研究结果表明：发情大鼠经历了稀释蔗糖溶液引起的正反馈信号强度的下降，芬氟拉明的厌食作用与发情大鼠正反馈信号的下降有关。(c) 2005爱思唯尔公司版权所有。
Meal size is decreased during the estrous stage of the rat's ovarian reproductive cycle. This is mediated, in part, by estradiol's ability to increase the strength by which negative-feedback signals function to inhibit meal size. For example, we recently reported that the anorectic effect of fenfluramine, a serotonin agonist, is enhanced during estrus. Here, we investigated whether a decrease in the strength of positive-feedback signals, like those related to the taste of food, contributes to the decrease in meal size observed either in estrous rats or following fenfluramine treatment. Rats were given brief access to six sucrose solutions (0.0, 0.025, 0.05, 0.1, 0.2, and 0.4 M) and the mean number of licks to these solutions was monitored in diestrous and estrous rats treated with 1 mg/kg fenfluramine or saline vehicle. Following saline treatment, estrous rats displayed fewer licks than diestrous rats to the 0.025 M sucrose solution. Following fenfluramine treatment, a decrease in the number of licks to 3 of the 5 sucrose solutions was observed in diestrous rats only. This decrease in sucrose palatability was limited to brief access tests, as overnight preference for the 0.025 M sucrose solution was not decreased by fenfluramine in either diestrous or estrous rats. Our findings suggest that: estrous rats experience a decrease in the strength of positive-feedback signals elicited by a dilute sucrose solution and that the anorectic effect of fenfluramine is associated with a decline in positive-feedback signaling in the diestrous rat. (c) 2005 Elsevier Inc. All rights reserved.