Miller B G, Tassell R, Stone G M
Aust J Biol Sci. 1982;35(4):417-25.
Progesterone (P) is anti-uterotrophic in the oestradiol (E2)-stimulated uterus of the mouse but not the sheep. To further understand this species difference, the time course of some early effects of a single injection of P on the E2-stimulated uterus has been examined. In the mouse, P caused a prompt (2-4 h) decline in uterine wet weight and in vitro rate of RNA synthesis, and a more gradual decrease (4-12 h) in RNA: DNA and protein: DNA ratios and in vitro rate of protein synthesis in whole uterus. In the sheep, P had no effect at any time on either whole uterus or caruncular endometrium. The results support the concepts that (1) anti-uterotrophic effects of P in E2-stimulated mice are mediated by a direct P effect on nuclear E2 receptor level, and (2) in the sheep P is not anti-uterotrophic because it does not regulate nuclear E2 receptor level.
孕酮（P）对雌二醇（E2）刺激的小鼠子宫具有抗子宫营养作用，但对绵羊子宫则无此作用。为了进一步了解这种物种差异，研究了单次注射P对E2刺激子宫的一些早期效应的时间进程。在小鼠中，P导致子宫湿重和体外RNA合成速率迅速下降（2 - 4小时），RNA：DNA和蛋白质：DNA比率以及全子宫体外蛋白质合成速率逐渐下降（4 - 12小时）。在绵羊中，P在任何时候对全子宫或肉阜子宫内膜均无影响。这些结果支持以下观点：（1）P对E2刺激的小鼠的抗子宫营养作用是由P对核E2受体水平的直接作用介导的；（2）在绵羊中，P不具有抗子宫营养作用是因为它不调节核E2受体水平。
