Rexroad C E
J Anim Sci. 1981 Oct;53(4):1057-69. doi: 10.2527/jas1981.5341057x.
Estradiol, progesterone, estradiol binding, and promegestone (R5020, a progestogen) binding were measured in the cytoplasmic an nuclear fractions of sheep myometrium on days O (estrus), 3, 6, 9, 12 and 15 of an estrous cycle. Estradiol and the numbers of unfilled estrogen binding sites were greatest at estrus in both the cytoplasm (.33 and 7.5 pmole/mg of DNA, respectively) and nuclei (.58 and 3.9 pmoles/mg DNA) and declined to low values by days 12 and 15 of the estrous cycle. The number of R5020 binding sites was greatest in both the cytoplasm (13.5 pmoles/mg of DNA) and nuclei (4.2 pmoles/mg of DNA) on days 0 and 3 of the estrous cycle). Progesterone in the tissues peaked on day 9 in the cytoplasm (2.0 pmoles/mg of DNA) and on day 6 in nuclei (1.2 pmoles/mg of DNA). High levels of estrogen binding and estradiol in the myometrium at estrus suggest that the marked stimulation or contractions at estrus by ovarian estrogens is mediated via myometrial binding of estrogen. High levels of progesterone were found when contractile activity was known to be relatively quiescent. High levels of progestogen binding found at estrus might play a role in progesterone-induced uterine quiescence during the luteal phase of the estrous cycle.
在发情周期的第0天（发情期）、第3天、第6天、第9天、第12天和第15天，测定了绵羊子宫肌层细胞质和细胞核部分的雌二醇、孕酮、雌二醇结合以及孕美雌酮（R5020，一种孕激素）结合情况。在发情期，细胞质（分别为0.33和7.5皮摩尔/毫克DNA）和细胞核（0.58和3.9皮摩尔/毫克DNA）中的雌二醇及未占据雌激素结合位点数量最多，到发情周期的第12天和第15天降至低值。在发情周期的第0天和第3天，细胞质（13.5皮摩尔/毫克DNA）和细胞核（4.2皮摩尔/毫克DNA）中的R5020结合位点数量最多。组织中的孕酮在细胞质中于第9天达到峰值（2.0皮摩尔/毫克DNA），在细胞核中于第6天达到峰值（1.2皮摩尔/毫克DNA）。发情期子宫肌层中高水平的雌激素结合和雌二醇表明，发情期卵巢雌激素对子宫肌层收缩的显著刺激是通过子宫肌层对雌激素的结合介导的。已知收缩活动相对静止时发现了高水平的孕酮。发情期发现的高水平孕激素结合可能在发情周期黄体期孕酮诱导的子宫静止中起作用。
