Sensibar J A, Griswold M D, Sylvester S R, Buttyan R, Bardin C W, Cheng C Y, Dudek S, Lee C
Department of Urology, Northwestern University Medical School, Chicago, Illinois 60611-3008.
Endocrinology. 1991 Apr;128(4):2091-102. doi: 10.1210/endo-128-4-2091.
The rat prostate is a complex ductal system with branches and subbranches extending from one end to another. Owing to the relative distance of various regions from the urethra, the entire length of the ductal system can be divided into three segments, i.e. the proximal, intermediate, and distal segments. The present study was carried out to examine the pattern of localization of sulfated glycoprotein-2 (SGP-2), a marker protein associated with programmed cell death, in various regions of the prostatic ductal system under normal conditions and during castration-induced regression. SGP-2 has been considered an androgen-repressed gene product in the rat prostate and has previously been known as castration-induced protein or TRPM-2. In the normal rat prostate, immunoreactive SGP-2 was localized in epithelial cells lining the proximal segment in which signs of programmed cell death were apparent. Cells lining the distal and intermediate segments were, however, devoid of SGP-2. This observed regional variation in SGP-2 localization did not support an earlier hypothesis which stated that SGP-2 was constitutively expressed by all prostatic epithelial cells in the normal rat prostate. After castration in adult rats, there was a shift in the location of cells containing SGP-2 from the proximal segment toward the distal segment. Therefore, there is a regional variation in the distribution of SGP-2 in the rat prostate both before and after castration in the host. These findings are likely to be associated with a regional variation in cellular responsiveness to androgen stimulation and androgen depletion in the prostatic ductal system. Results also support the view that SGP-2 localization is associated with an early manifestation of programmed cell death in the rat prostate.
大鼠前列腺是一个复杂的导管系统，其分支和亚分支从一端延伸到另一端。由于各个区域距尿道的相对距离不同，导管系统的全长可分为三段，即近端段、中间段和远端段。本研究旨在检测硫酸化糖蛋白-2（SGP-2）的定位模式，SGP-2是一种与程序性细胞死亡相关的标记蛋白，在正常条件下以及去势诱导的退化过程中，观察其在前列腺导管系统各区域中的定位情况。SGP-2被认为是大鼠前列腺中一种受雄激素抑制的基因产物，此前被称为去势诱导蛋白或TRPM-2。在正常大鼠前列腺中，免疫反应性SGP-2定位于近端段的上皮细胞中，在这些细胞中程序性细胞死亡的迹象很明显。然而，远端段和中间段的上皮细胞中没有SGP-2。观察到的SGP-2定位的区域差异并不支持早期的假说，该假说认为SGP-2在正常大鼠前列腺中由所有前列腺上皮细胞组成性表达。成年大鼠去势后，含有SGP-2的细胞的位置从近端段向远端段转移。因此，在宿主去势前后，大鼠前列腺中SGP-2的分布存在区域差异。这些发现可能与前列腺导管系统中细胞对雄激素刺激和雄激素耗竭的反应性区域差异有关。结果还支持这样一种观点，即SGP-2的定位与大鼠前列腺程序性细胞死亡的早期表现有关。
