Yucel S, Cavalcanti A G, Desouza A, Wang Z, Baskin L S
UCSF Children's Medical Center, Departments of Urology and Paediatrics, University of California, San Francisco, USA.
BJU Int. 2003 Dec;92(9):1016-21. doi: 10.1111/j.1464-410x.2003.04511.x.
To describe the effects of exogenous oestrogens and androgens on urethral formation in the mouse, as the development of the mouse and human urethra have significant similarities, and understanding normal male urethral development may help to identify the causes of abnormal development, e.g. hypospadias.
Timed-pregnant C57/6 mice were exposed to synthetic oestrogens and androgens. The morphology of the genital tubercles was examined histologically and with three-dimensional computer reconstruction. Specific attention was focused on the developing urethral seam.
Microscopic serial analysis confirmed the presence of an arrest in seam formation in about half of oestrogen-treated male fetuses. In contrast, there was acceleration of urethral fold fusion and a longer urethral tube in those treated with androgens. Oestrogen-treated fetuses had a thin periurethral spongiosa, in contrast to androgen-treated fetuses which developed a thicker periurethral spongiosa. The effect of oestrogens on seam area formation did not depend on the dose, but in contrast, in the androgen-treated fetuses it was.
Oestrogens and androgens have a direct effect on the fusion of the urethral fold that leads to seam formation. Normal urethral development depends on the delicate balance of these complementary hormones.
描述外源性雌激素和雄激素对小鼠尿道形成的影响，因为小鼠和人类尿道的发育有显著相似性，了解正常男性尿道发育可能有助于确定异常发育的原因，如尿道下裂。
对处于特定孕期的C57/6小鼠给予合成雌激素和雄激素。通过组织学检查和三维计算机重建来观察生殖结节的形态。特别关注发育中的尿道缝。
显微镜下的系列分析证实，约一半接受雌激素处理的雄性胎儿的尿道缝形成出现停滞。相比之下，接受雄激素处理的胎儿尿道褶融合加速，尿道管更长。接受雌激素处理的胎儿尿道周围海绵体较薄，而接受雄激素处理的胎儿则发育出较厚的尿道周围海绵体。雌激素对尿道缝区域形成的影响不取决于剂量，但相反，在接受雄激素处理的胎儿中则取决于剂量。
雌激素和雄激素对导致尿道缝形成的尿道褶融合有直接影响。正常尿道发育取决于这些互补激素的微妙平衡。
