Stirnemann B, Bouftila B, Clabaut M
Laboratoire de physiopathologie foetomaternelle, faculté des sciences, université de Rouen, Mont-Saint-Aignan, France.
C R Acad Sci III. 1997 Jan;320(1):19-25. doi: 10.1016/s0764-4469(99)80082-1.
The objective of this investigation was to examine the effects of 4-hydroxytamoxifen on the uterine activity. For this, we evaluated the electrical activity of the myometrium, chronically, in conscious unrestrained rats at mid-pregnancy. We also examined the tissular progesterone and 17 beta-estradiol concentrations in the myometrium and uterus 6 hours after administration of 4-hydroxytamoxifen. Comparison of myometrial electrical activities recorded during the control period with those obtained during the two periods (6 and 24 hours) after administration of 4-hydroxytamoxifen (80 micrograms.kg-1, s.c.) showed an increase in simultaneity of uterine contractions (P < 0.01). Tissular steroid hormone measurement by radioimmunoassay shows a fall of progesterone in the myometrium (P < 0.001) and of 17 beta-estradiol in the uterus (P < 0.01), 6 hours after administration of 4-hydroxytamoxifen. In the myometrium, for 50% of animals, 17 beta-estradiol concentration decreased (P < 0.01) and for 50% of animals it increased (P < 0.05). The decrease in progesterone is significant in the myometrium and in the whole uterus (respectively P < 0.001 and P < 0.01), 24 hours after administration of 4-hydroxytamoxifen. The 17 beta-estradiol concentration significantly decreased for all animals in the myometrium (P < 0.01) and in the uterus (P < 0.01), after this time. It appears that variation in progesterone induces the activation of uterine motility and exerts an effect on some factors involved in the regulation of the rat myometrium at mid-pregnancy.
本研究的目的是检测4-羟基他莫昔芬对子宫活动的影响。为此，我们在妊娠中期对清醒无束缚的大鼠子宫肌层的电活动进行了长期评估。我们还检测了在给予4-羟基他莫昔芬6小时后子宫肌层和子宫组织中的孕酮及17β-雌二醇浓度。将给药前对照期记录的子宫肌层电活动与给予4-羟基他莫昔芬（80微克·千克-1，皮下注射）后6小时和24小时记录的电活动进行比较，结果显示子宫收缩同步性增加（P<0.01）。放射免疫法检测组织类固醇激素显示，给予4-羟基他莫昔芬6小时后，子宫肌层孕酮水平下降（P<0.001），子宫中17β-雌二醇水平下降（P<0.01）。在子宫肌层中，50%的动物17β-雌二醇浓度下降（P<0.01），50%的动物17β-雌二醇浓度升高（P<0.05）。给予4-羟基他莫昔芬24小时后，子宫肌层和整个子宫中的孕酮水平均显著下降（分别为P<0.001和P<0.01）。此后，所有动物子宫肌层和子宫中的17β-雌二醇浓度均显著下降（P<0.01）。孕酮的变化似乎诱导了子宫运动的激活，并对妊娠中期大鼠子宫肌层调节的一些因素产生影响。
