Estrogen suppresses retinaldehyde dehydrogenase 1 expression in the anterior pituitary glands of female rats
Estrogen suppresses retinaldehyde dehydrogenase 1 expression in the anterior pituitary glands of female rats
复制标题
DOI：
10.1507/endocrj.k07-101
复制
发表时间：
2008-02-01
影响因子：
2
通讯作者：
Yashiro, Takashi
中科院分区：
文献类型：
--
作者：
Fujiwara, Ken;Davaadash, Bulgan;Yashiro, Takashi
视黄酸 (RA) 在细胞生长和组织发育中起着至关重要的作用。 RA也是垂体功能的调节因素。 RA 是由类维生素A 通过氧化过程合成的。视黄醛氧化成 RA 是由视黄醛脱氢酶 (RALDH) 催化的，包括 RALDH1、RALDH2 和 RALDH3。最近，我们证明 RALDH1 在成年雄性大鼠的垂体前叶中表达。然而，RALDH1在女性垂体中的表达以及RALDH1表达的调控尚未确定。因此，我们检测了成年雌性大鼠垂体中 RALDH1 mRNA 的表达。通过地高辛标记的cRNA探针原位杂交和实时定量PCR分析，我们发现发情期RALDH1的表达水平明显低于发情前期、发情后期和发情间期。 RALDH1 mRNA 水平在卵巢切除术后增加，并在 17 β-雌二醇植入治疗 1 周后显着下降。雌二醇（每只大鼠0.01-100μg）皮下注射24小时后，剂量依赖性地降低垂体中RALDH1的表达。这些结果清楚地表明 RALDH1 mRNA 表达受到雌激素的抑制。我们推测RA的产生受到雌激素的调节，并且RA通过雌性大鼠垂体前叶的旁分泌和/或自分泌机制在发情周期中发挥作用。
Retinoic acid (RA) plays a critical role in cell growth and tissue development. RA is also a regulating factor of pituitary function. RA is synthesized from retinoids through oxidation processes. The oxidation of retinal to RA is catalyzed by the retinaldehyde dehydrogenases (RALDHs), including RALDH1, RALDH2 and RALDH3. Recently, we demonstrated that RALDH1 is expressed in the anterior pituitary glands of adult male rats. However, the expression of RALDH1 in the female pituitary gland and the regulation of RALDH1 expression have not been determined. Therefore, we examined the expression of RALDH1 mRNA in the pituitary glands of adult female rats. By in situ hybridization with digoxigenin-labeled cRNA probes and quantitative real-time PCR analysis, we found that the expression level of RALDH1 was significantly lower in estrus as compared to proestrus, metestrus and diestrus. RALDH1 mRNA levels increased after ovariectomy and decreased remarkably after a 1-week treatment with 17 beta-estradiol implants. Estradiol (0.01-100 mu g per rat) dose-dependently decreased the expression of RALDH1 in the pituitary glands after 24 hours of subcutaneous administration. These results clearly show that RALDH1 mRNA expression is suppressed by estrogen. We speculate that the generation of RA is regulated by estrogen and that RA plays a role in the estrus cycle through paracrine and/or autocrine mechanisms in the anterior pituitary gland of female rats.