Asano Kosuke, Maruyama Satoshi, Usui Tsuguru, Fujimoto Nariaki
Department of Developmental Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8553, Japan.
Endocr J. 2003 Jun;50(3):281-7. doi: 10.1507/endocrj.50.281.
Although ER beta is known to be expressed at high levels in the rat prostate gland, its regulation is not well understood. Here we examined ER mRNA expression and the effects of testosterone administration in male rats at 1, 4 and 9 weeks of age who were castrated and/or treated with testosterone for a week, and then sacrificed. ER alpha was the major type of ER expressed in 2 week-old animals while dominant expression of ER beta mRNA was apparent in older age groups. Interestingly while ER beta expression was diminished and ER alpha mRNA increased in the castrated group, testosterone administration reversed this effect. A time-course study indicated that induction of ER beta mRNA increased within 9 hr and ER alpha decreased in 2 days after an injection (i.p.) of testosterone. Our results suggested that 1) testosterone up-regulates ER beta mRNA expression while ER alpha is down-regulated; and that 2) great changes in ER alpha and beta expression in the prostate gland during development from the newborn to adult may be due to the influence of testosterone.
尽管已知雌激素受体β（ERβ）在大鼠前列腺中高水平表达，但其调控机制尚未完全明确。在此，我们检测了1周龄、4周龄和9周龄雄性大鼠在去势和/或接受睾酮治疗1周后处死时的ER mRNA表达及睾酮给药的影响。雌激素受体α（ERα）是2周龄动物中表达的主要ER类型，而ERβ mRNA在年龄较大的组中占主导表达。有趣的是，在去势组中ERβ表达减少而ERα mRNA增加，而睾酮给药则逆转了这种效应。一项时间进程研究表明，腹腔注射睾酮后9小时内ERβ mRNA诱导增加，2天内ERα减少。我们的结果表明：1）睾酮上调ERβ mRNA表达，同时下调ERα；2）从新生到成年发育过程中前列腺中ERα和β表达的巨大变化可能归因于睾酮的影响。
