Sensibar J A, Qian Y, Griswold M D, Sylvester S R, Bardin C W, Cheng C Y, Lee C
Department of Urology, Northwestern University Medical School, Chicago, Illinois 60611.
Biol Reprod. 1993 Aug;49(2):233-42. doi: 10.1095/biolreprod49.2.233.
In the rat reproductive tract, sulfated glycoprotein 2 (SGP-2) is present in the ventral prostate, seminal vesicle, testis, and epididymis. In the ventral prostate, SGP-2 is associated with the process of programmed cell death, while in the testis and epididymis a role for SGP-2 in sperm maturation has been proposed. Available information suggests that there are both inter- and intra-organ variations in SGP-2 localization, molecular forms, and response to androgen ablation. In the present study, localization of SGP-2 within the ventral prostate, seminal vesicle, and epididymis was compared by immunohistochemistry. In the ventral prostate of intact rats, immunoreactive SGP-2 was confined to a discrete population of epithelial cells lining the proximal ducts. Epithelial cells in other regions of the ventral prostate did not stain for SGP-2. A similar staining pattern was observed for the seminal vesicle; a small population of SGP-2-expressing epithelial cells was found in epithelium that did not stain for SGP-2. The epididymis also demonstrated a non-uniform staining pattern. The caput displayed strong immunoperoxidase reaction over the apical membrane and stereocilia of all principal cells. Principal cells also showed variable degrees of cytoplasmic staining ranging from weak to strongly positive. The corpus and cauda showed a similar staining pattern. After castration, all epithelial cells in the ventral prostate and seminal vesicle became intensely positive for SGP-2 staining. In the caput and cauda epididymis there was an increase in the number of principal cells demonstrating strong intracellular staining for SGP-2. These results suggest that as observed previously in the regressing ventral prostate, increased intracellular SGP-2 staining may also be associated with the regressing epididymis and seminal vesicle. Differences in molecular forms of SGP-2 were investigated by two-dimensional Western and lectin blots. Molecular forms of SGP-2 differed between testis and epididymis but were similar between ventral prostate and seminal vesicle. Prostate and seminal vesicle forms of SGP-2 differed from those of both testis and epididymis. Analysis of terminal carbohydrate present on the various SGP-2 molecular forms also confirmed the existence of heterogeneity. These results demonstrate the presence of multiple molecular forms of SGP-2 in various organs of the male reproductive tract in rats and suggest a possible variation in functional activity and/or half-life of SGP-2 in these organs.
在大鼠生殖道中，硫酸化糖蛋白2（SGP - 2）存在于腹侧前列腺、精囊、睾丸和附睾中。在腹侧前列腺中，SGP - 2与程序性细胞死亡过程相关，而在睾丸和附睾中，有人提出SGP - 2在精子成熟过程中发挥作用。现有信息表明，SGP - 2在定位、分子形式以及对雄激素去除的反应方面存在器官间和器官内的差异。在本研究中，通过免疫组织化学比较了SGP - 2在腹侧前列腺、精囊和附睾中的定位。在完整大鼠的腹侧前列腺中，免疫反应性SGP - 2局限于近端导管内衬的离散上皮细胞群体。腹侧前列腺其他区域的上皮细胞未被SGP - 2染色。精囊也观察到类似的染色模式；在未被SGP - 2染色的上皮中发现了一小群表达SGP - 2的上皮细胞。附睾也呈现出不均匀的染色模式。附睾头在所有主细胞的顶膜和静纤毛上显示出强烈的免疫过氧化物酶反应。主细胞还表现出不同程度的细胞质染色，从弱阳性到强阳性不等。附睾体和附睾尾显示出类似的染色模式。去势后，腹侧前列腺和精囊中的所有上皮细胞对SGP - 2染色均呈强阳性。在附睾头和附睾尾中，显示SGP - 2细胞内强染色的主细胞数量增加。这些结果表明，如先前在退化的腹侧前列腺中所观察到的，细胞内SGP - 2染色增加也可能与退化的附睾和精囊有关。通过二维蛋白质印迹和凝集素印迹研究了SGP - 2的分子形式差异。SGP - 2的分子形式在睾丸和附睾之间不同，但在腹侧前列腺和精囊之间相似。前列腺和精囊中的SGP - 2形式与睾丸和附睾中的不同。对各种SGP - 2分子形式上存在的末端碳水化合物的分析也证实了异质性的存在。这些结果证明了大鼠雄性生殖道各器官中存在多种SGP - 2分子形式，并表明这些器官中SGP - 2的功能活性和/或半衰期可能存在差异。
