Verhoeven G, Deboel L, Swinnen J, Rombauts L, Vanderhoydonc F, Rosseels J, Hoeben E, Heyns W
Laboratory for Experimental Medicine and Endocrinology, Onderwijs en Navorsing, Gasthuisberg, Catholic University of Leuven, Belgium.
Int J Androl. 1995 Feb;18(1):23-34. doi: 10.1111/j.1365-2605.1995.tb00931.x.
To study the effect of androgens on somatic testicular cells, rats were rendered germ cell depleted by prenatal irradiation (RX). Adult RX rats were treated with a desensitizing dose of a GnRH agonist (GnRHa; Zoladex), combined with an antiandrogen (Nilutamide) to preclude all androgen effects, or combined with testosterone or hCG to restore androgen action. The effect of these treatments for 3 weeks on the weight of testes and accessory sex glands, hormones (LH, FSH, testosterone, inhibin), testicular proteins, the pattern of incorporation of [35S]-methionine into testicular proteins (studied by two dimensional gel electrophoresis) and steady state mRNA levels for transferrin and androgen-binding protein (ABP) were evaluated. Combined treatment with GnRHa and antiandrogen virtually eliminated gonadotrophins, androgens and androgen effects. Testicular weight was reduced to 50% of that observed in RX controls. Treatment with GnRHa and testosterone resulted in supraphysiological levels of testosterone and testicular weights comparable to those observed in RX controls. FSH levels in these animals, however, were in the normal range. A low dose of hCG also restored testicular weight in the presence of low concentrations of serum testosterone and low normal levels of FSH. Neither polyacrylamide gel electrophoresis of total testicular proteins nor two dimensional gel electrophoresis of [35S]-methionine labelled proteins revealed striking changes in distinct testicular proteins as a result of androgen withdrawal or androgen treatment. Dot blot hybridization showed a three-fold increase in the mRNA level for ABP (expressed per microgram total RNA) in the Sertoli cell enriched testes of RX rats. This level was barely influenced by androgen withdrawal or androgen administration. The mRNA level for transferrin was increased six-fold in RX rats. A 50% reduction of this level was observed after combined treatment with GnRHa and antiandrogen. It is concluded that, in the germ cell-depleted testis, the major effect of androgens is an overall increase in protein and RNA synthesis rather than a very important and selective increase of a few gene products.
为研究雄激素对睾丸体细胞的作用，通过产前照射（RX）使大鼠生殖细胞耗竭。成年RX大鼠接受促性腺激素释放激素激动剂（GnRHa；诺雷德）脱敏剂量治疗，联合抗雄激素药物（尼鲁米特）以排除所有雄激素作用，或联合睾酮或人绒毛膜促性腺激素（hCG）以恢复雄激素作用。评估这些治疗3周对睾丸和附属性腺重量、激素（促黄体生成素、促卵泡生成素、睾酮、抑制素）、睾丸蛋白、[35S] - 甲硫氨酸掺入睾丸蛋白的模式（通过二维凝胶电泳研究）以及转铁蛋白和雄激素结合蛋白（ABP）的稳态mRNA水平的影响。GnRHa与抗雄激素联合治疗几乎消除了促性腺激素、雄激素及雄激素作用。睾丸重量降至RX对照组的50%。GnRHa与睾酮治疗使睾酮水平高于生理水平，睾丸重量与RX对照组相当。然而，这些动物的促卵泡生成素水平在正常范围内。低剂量hCG在血清睾酮浓度低和促卵泡生成素水平正常偏低的情况下也恢复了睾丸重量。无论是睾丸总蛋白的聚丙烯酰胺凝胶电泳还是[35S] - 甲硫氨酸标记蛋白的二维凝胶电泳，均未显示出因雄激素撤除或雄激素治疗而导致明显的睾丸特异性蛋白变化。斑点印迹杂交显示，RX大鼠富含支持细胞的睾丸中，ABP的mRNA水平（以每微克总RNA表示）增加了三倍。该水平几乎不受雄激素撤除或雄激素给药的影响。RX大鼠中转铁蛋白的mRNA水平增加了六倍。GnRHa与抗雄激素联合治疗后，该水平降低了50%。得出的结论是，在生殖细胞耗竭的睾丸中，雄激素的主要作用是总体上增加蛋白质和RNA合成，而不是非常显著且选择性地增加少数基因产物。
