Toney T W, Danzo B J
Department of Obstetrics and Gynecology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232.
Endocrinology. 1989 Jul;125(1):231-42. doi: 10.1210/endo-125-1-231.
To obtain evidence of a physiological role for androgens and estrogens in the regulation of the epididymis of sexually immature rabbits, the effects of these hormones on [35S] methionine incorporation into epididymal proteins in vitro were examined. Two-dimensional polyacrylamide gel electrophoresis revealed that short term incubation with estradiol changed the patterns of radiolabeled proteins detected in tissue homogenates of epididymal segments from castrated rabbits compared to those in segments from castrated rabbits that were not exposed to exogenous estradiol. Most of the changes seen in corpus tissue affected proteins with a wide range of pI values and relatively high mol wt (greater than 40K). The effects on caput and cauda tissue proteins were seen over a wide pH and mol wt range. Castration abolished many of the regional differences in protein synthesis; these were restored by incubation with estradiol. Testosterone had little effect on the synthesis of tissue proteins, except for stimulation of the synthesis of a single protein (17K; pI 5.1) in all three segments and stimulation of a small group of proteins (less than 14K; pI 7.0-7.2) in the corpus. Estradiol had little effect on proteins secreted by epididymal segments. Testosterone, however, stimulated the synthesis of a number of unique proteins secreted by the caput and corpus and resulted in a pattern of radiolabeled proteins similar to that obtained with intact animals. Additional secretory proteins could be stimulated in caput, but not corpus, tissue minces from intact rabbits by exogenous testosterone. No androgen-specific synthesis of secretory proteins was detected in the cauda of either castrated or intact rabbits. Estradiol affected the synthesis of both secreted and tissue proteins in terms of influencing which epididymal segment was most active at incorporating [35S]methionine into radiolabeled proteins and which was least active. Testosterone had a similar influence on secreted proteins, but did not have any analogous effect on tissue proteins. These results indicate that testosterone and estradiol influence the synthesis of proteins by the immature rabbit epididymis and that both may, therefore, be important physiological regulators of epididymal development and/or function.
为了获得雄激素和雌激素在性未成熟兔子附睾调节中发挥生理作用的证据，研究了这些激素对体外附睾蛋白中[35S]甲硫氨酸掺入的影响。二维聚丙烯酰胺凝胶电泳显示，与未暴露于外源性雌二醇的去势兔子附睾段组织匀浆相比，用雌二醇短期孵育改变了去势兔子附睾段组织匀浆中检测到的放射性标记蛋白的模式。在体部组织中观察到的大多数变化影响了具有广泛pI值和相对较高分子量（大于40K）的蛋白质。对头部和尾部组织蛋白的影响在较宽的pH和分子量范围内可见。去势消除了蛋白质合成中的许多区域差异；通过与雌二醇孵育可恢复这些差异。睾酮对组织蛋白的合成影响很小，除了刺激所有三个节段中单一蛋白质（17K；pI 5.1）的合成以及刺激体部中一小群蛋白质（小于14K；pI 7.0 - 7.2）的合成。雌二醇对附睾段分泌的蛋白质影响很小。然而，睾酮刺激了头部和体部分泌的许多独特蛋白质的合成，并导致放射性标记蛋白质的模式与完整动物相似。外源性睾酮可刺激完整兔子头部而非体部组织匀浆中额外分泌蛋白的合成。在去势或完整兔子的尾部均未检测到雄激素特异性分泌蛋白的合成。就影响哪个附睾段在将[35S]甲硫氨酸掺入放射性标记蛋白方面最活跃以及哪个最不活跃而言，雌二醇影响了分泌蛋白和组织蛋白的合成。睾酮对分泌蛋白有类似影响，但对组织蛋白没有任何类似作用。这些结果表明，睾酮和雌二醇影响未成熟兔子附睾的蛋白质合成，因此两者可能都是附睾发育和/或功能的重要生理调节因子。
