Lephart E D, Simpson E R, Trzeciak W H
Cecil H. and Ida Green Center for Reproductive Biology Sciences, Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235.
J Mol Endocrinol. 1991 Apr;6(2):163-70. doi: 10.1677/jme.0.0060163.
To investigate the effects of sex hormones on 5 alpha-reductase, we examined 5 alpha-reductase mRNA content and enzyme activity in the adrenal cortex of peripubertal male and female rats. In male rats, the influence of castration or hormone-replacement treatment with dihydrotestosterone (5 alpha-DHT) on 5 alpha-reductase was assessed. To stimulate ovarian sex hormone production in immature female rats, the effect of a single injection of 5 IU pregnant mare serum gonadotrophin (PMSG) on 5 alpha-reductase was examined. The efficacy of the treatments was demonstrated by measuring serum LH and ventral prostate weight in male rats, and serum oestradiol and ovarian weight in female rats. Growth hormone was also measured across all treatments in male and female rats. Adrenal 5 alpha-reductase mRNA levels were determined by RNA blot analysis utilizing a rat 5 alpha-reductase cDNA as probe. 5 alpha-Reductase enzyme activity was estimated by isolating [3H]5 alpha-DHT by thin-layer chromatography after incubation with [3H]testosterone. The identity of the [3H]5 alpha-DHT formed was demonstrated by recrystallization of the derivatized DHT to constant specific activity. In controls, adrenal cortical 5 alpha-reductase mRNA content was nearly four times higher in immature female rats compared with intact peripubertal males. Castration resulted in a sevenfold increase in adrenal 5 alpha-reductase mRNA content compared with that in intact controls, while in DHT-injected castrated animals the mRNA level was nearly undetectable. The content of adrenal 5 alpha-reductase mRNA in anoestrous rats was nearly four times higher than in PMSG-treated animals.(ABSTRACT TRUNCATED AT 250 WORDS)
为研究性激素对5α-还原酶的影响，我们检测了青春期前后雄性和雌性大鼠肾上腺皮质中5α-还原酶的mRNA含量及酶活性。在雄性大鼠中，评估了去势或用双氢睾酮（5α-DHT）进行激素替代治疗对5α-还原酶的影响。为刺激未成熟雌性大鼠的卵巢性激素分泌，检测了单次注射5国际单位孕马血清促性腺激素（PMSG）对5α-还原酶的影响。通过测量雄性大鼠的血清促黄体生成素（LH）和腹侧前列腺重量，以及雌性大鼠的血清雌二醇和卵巢重量，证实了治疗的效果。还测量了所有处理组雄性和雌性大鼠的生长激素。利用大鼠5α-还原酶cDNA作为探针，通过RNA印迹分析测定肾上腺5α-还原酶的mRNA水平。与[3H]睾酮孵育后，通过薄层层析分离[3H]5α-DHT来估算5α-还原酶的活性。通过将衍生化的双氢睾酮重结晶至恒定比活性，证实了所形成的[3H]5α-DHT的同一性。在对照组中，未成熟雌性大鼠肾上腺皮质5α-还原酶的mRNA含量比青春期前后的完整雄性大鼠高近四倍。与完整对照组相比，去势导致肾上腺5α-还原酶的mRNA含量增加了七倍，而在注射DHT的去势动物中，mRNA水平几乎检测不到。处于乏情期的大鼠肾上腺5α-还原酶mRNA的含量比PMSG处理的动物高近四倍。（摘要截短于250字）
