Instituto Mexicano del Seguro Social, Unidad de Investigacion Medica en Farmacologia, Mexico DF.
Horm Metab Res. 2013 Jul;45(7):490-4. doi: 10.1055/s-0033-1337932. Epub 2013 Apr 3.
Most studies on the effect of tibolone on the uterus have focused on the endometrium dismissing the importance of the myometrium. The aim of the present study was to investigate some estrogen-like actions of tibolone in the uterus assessed by: 1) the expression of estrogen, progesterone, and serotonin receptors, and 2) the myometrial contraction induced by serotonin. Estradiol (250 μg), progesterone (50 mg), or testosterone (25 mg) pellets were implanted to ovariectomized rats. Tibolone (0.5 mg/day) was orally administered. An implanted pellet containing vehicle or an equivalent volume of water p.o., were used as controls. Sixty days after beginning the treatments, rats were killed and uterus removed. One horn was processed to evaluate estrogen-alpha, progesterone A and B, and serotonin-2A receptors expression, and the other one was used for studying contraction to serotonin and 60 mM potassium solution. The present data showed that tibolone-induced expression of estrogen, progesterone, and serotonin receptors, but did not induce uterine contractile response to either serotonin or potassium solution. These findings suggest that, in the uterus, tibolone may exert molecular estrogenic actions such as the induction of receptor expression, but not a physiological response as the estrogen-dependent contraction to serotonin.
大多数关于替勃龙对子宫影响的研究都集中在内膜上，而忽略了子宫肌层的重要性。本研究的目的是通过以下两种方法来研究替勃龙在子宫中的一些类雌激素作用：1）雌激素、孕激素和 5-羟色胺受体的表达，以及 2）5-羟色胺诱导的子宫平滑肌收缩。将雌二醇（250μg）、孕酮（50mg）或睾酮（25mg）微球植入去卵巢大鼠。替勃龙（0.5mg/天）经口给药。植入含有载体或等体积水的微球作为对照。治疗开始 60 天后，处死大鼠并取出子宫。一个子宫角用于评估雌激素-α、孕激素 A 和 B 以及 5-羟色胺 2A 受体的表达，另一个子宫角用于研究对 5-羟色胺和 60mM 钾溶液的收缩反应。本研究数据表明，替勃龙诱导了雌激素、孕激素和 5-羟色胺受体的表达，但不能诱导子宫对 5-羟色胺或钾溶液产生依赖于雌激素的收缩反应。这些发现表明，替勃龙在子宫中可能发挥分子雌激素作用，如诱导受体表达，但不会产生类似于 5-羟色胺依赖性收缩的生理反应。
