Hendry W J, Danzo B J
J Steroid Biochem. 1985 Dec;23(6A):883-93. doi: 10.1016/0022-4731(85)90043-3.
Epididymides from sexually mature rabbits contain a factor that induces a discrete reduction in the sedimentation coefficient of cytosolic estrogen receptors from various tissues (rabbit epididymis and accessory sex organs; rabbit, rat and mouse uterus) and of cytosolic progesterone receptors from the rabbit uterus. The factor is not species-specific since a similar activity was detected in extracts of mature rat epididymides. Although present in cytosol, the factor is obtained in much higher yield in hypertonic extracts of the nucleomyofibrillar fraction of mature rabbit epididymal tissue. Using rabbit uterine estrogen receptor as substrate, we have determined the following details about the rabbit epididymal factor: (1) it is tissue-specific (undetectable in extracts from rabbit accessory sex organs, testis, uterus, liver, lung, kidney and intestine); (2) it is age-dependent (undetectable in extracts from sexually immature rabbit epididymides); (3) its maintenance is testis-independent following its post-pubertal induction or activation; (4) it is primarily localized in the caput region of the epididymis; (5) it is inactivated by elevated temperature; (6) it is macromolecular in nature; (7) it is DNase- and RNase-resistant; (8) it is irreversibly inactivated by leupeptin, indicating that it is a protease; and (9) it is effective on unoccupied and occupied receptors.
性成熟兔子的附睾中含有一种因子，该因子能使来自各种组织（兔子附睾和附属生殖器官；兔子、大鼠和小鼠子宫）的胞质雌激素受体以及兔子子宫的胞质孕酮受体的沉降系数发生明显降低。该因子并非物种特异性的，因为在成熟大鼠附睾提取物中也检测到了类似活性。尽管该因子存在于胞质溶胶中，但在成熟兔子附睾组织的核肌原纤维部分的高渗提取物中能获得更高产量。以兔子子宫雌激素受体为底物，我们确定了关于兔子附睾因子的以下细节：（1）它具有组织特异性（在兔子附属生殖器官、睾丸、子宫、肝脏、肺、肾脏和肠道的提取物中未检测到）；（2）它与年龄有关（在性未成熟兔子附睾的提取物中未检测到）；（3）青春期后诱导或激活后，其维持不依赖于睾丸；（4）它主要定位于附睾的头部区域；（5）它在温度升高时失活；（6）它本质上是大分子；（7）它对DNase和RNase具有抗性；（8）它被亮肽素不可逆地失活，表明它是一种蛋白酶；（9）它对未占据和已占据的受体均有效。
