Estrogen replacement reverses ovariectomy-induced vaginal hyperalgesia in the rat
Estrogen replacement reverses ovariectomy-induced vaginal hyperalgesia in the rat
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DOI：
10.1016/s0378-5122(01)00261-4
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发表时间：
2002-02-26
期刊：
影响因子：
4.9
通讯作者：
Berkley, KJ
中科院分区：
文献类型：
--
作者：
Bradshaw, HB;Berkley, KJ
目的：女性因年龄增长或卵巢切除导致的卵巢功能丧失往往与阴道痛觉过敏的发展有关，而雌激素替代治疗可以缓解这种痛觉过敏。这项研究考察了大鼠卵巢切除是否同样会引起阴道痛觉过敏，如果是的话，雌激素替代是否会缓解这种情况。方法：训练雌性大鼠通过给位于阴道中段的气囊充气来产生逃避阴道扩张的手术反应。将正常循环大鼠对八种不同充气的逃逸反应百分比与卵巢切除(OVX)或假卵巢切除(ShamOVX)后的相同大鼠的测量结果进行了比较。OVX组给予雌激素替代(OVX+E_2)。还测量了八个体积对阴道壁施加的压力，从而可以评估阴道张力。结果：与骑自行车时的反应相比，OVX后的总体逃避反应百分率显著高于骑自行车时的反应，而ShamOVX的总体逃避反应百分率在最大六个扩张容量时显著高于骑自行车时的反应，但痛敏量存在个体差异。在OVX+E2后，除一只大鼠外，所有大鼠的逃避反应百分比都下降了。OVX、ShamOVX或OVX+E_2组大鼠的阴道张力与整体阴道张力无差异。结论：大鼠去卵巢可引起不同程度的阴道痛觉过敏，多数情况下雌激素替代可减轻痛觉过敏。因此，去卵巢大鼠似乎为研究与女性卵巢功能丧失相关的性交困难的机制提供了一个有用的模型。(C)2002爱思唯尔科学爱尔兰有限公司。保留所有权利。
Objectives: The loss of ovarian function in women through aging or oophorectomy is often associated with the development of vaginal hyperalgesia that can be alleviated with estrogen replacement. This study examined if ovariectomy in rats would similarly give rise to vaginal hyperalgesia, and, if so, whether estrogen replacement would alleviate it. Methods: Female rats were trained to perform an operant response to escape vaginal distention delivered by inflating a balloon located in mid-vaginal canal. Percent escape responses to eight different volumes of distention measured in normally cycling rats were compared with measures made in the same rats following ovariectomy (OVX) or sham ovariectomy (shamOVX). and then, in the OVX group, estrogen replacement (OVX + E2). Pressures exerted by the eight volumes on the vaginal wall were also measured, thereby permitting assessment of vaginal tone. Results: Whereas overall escape response percentages after OVX, but not shamOVX, were significantly higher to the largest six distention volumes compared with responses during cycling, there were individual differences in the amount of hyperalgesia. Following OVX + E2, escape response percentages decreased in all but one rat. Vaginal tone after OVX shamOVX or OVX + E2 did not differ From overall vaginal tone in cycling rats. Conclusions: Ovariectomy in rats evokes a variable amount of vaginal hyperalgesia that can be alleviated by estrogen replacement in most cases. Thus, the ovariectomized rat appears to provide a useful model for the study of mechanisms underlying the dyspareunia that is associated with loss of ovarian function in women. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.