Regulation mechanisms of transcription of sex steroidogenic enzymes during follicular growth in the chicken.

鸡卵泡生长过程中性类固醇生成酶转录的调节机制。

基本信息

批准号：
04454106
负责人：
SHIMADA Kiyoshi
金额：
$ 3.01万
依托单位：
Nagoya University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1992
资助国家：
日本
起止时间：
1992 至 1994
项目状态：
已结题

项目摘要

Concentrations of estradiol (E), testosterone (T) and progesterone (P), and levels of the 1.9-kb and 4.0-kb mRNA encoding P450_<17alpha> hydroxylase(P450_<17alpha>) and P450_<aromatase> (P450_<arom>), respectively, were measured in the isolated granulosa, theca interna and theca externa of the largest preovulatory (F1-F4) follicles of the chicken 20 h and 3 h before expected ovulation of F1. In the granulosa layr, E and T concentrations remained low throughout this period of follicular growth, whereas P concentrations were high 3 h before ovulation in F2 and F1 follicles. Estradiol levels were highest in the theca interna and externa of the amallest (F4) follicle, decreasing progressively with follicular growth. Testosterone content of theca interna and granulosa was greater in less mature F4-F2 follicles than that found in the most mature (F1) follicle, whereas theca externa contained little T.P was quantifiable in significant amounts only in granulosa tissue, peaking in F2 and F1 follicles at 3 h before ovulation, at which time plasma levels of steroids also rose significantly. P450_<17alpha> was expressed mainly in theca interna, whereas P450_<arom> mRNA levels found in theca externa refiected the pattern of E in this compartment. Expression of these two genes was very low in granulosa tissue, remaining unchanged during follicular growth. These results indicate that E and T synthesis in the chicken ovary is regulated, at least in part, at mRNA levels of P450_<17alpha> and P450_<arom> in the theca interna and theca externa layrs during follicular growth.

雌二醇（E），睾丸激素（T）和孕酮（P）的浓度以及1.9-Kb和4.0 kb的水平和编码P450_ <17Alpha>羟基酶（p450_ <17Alpha>）的浓度，分别是分离的（p450_ <17alpha>）和p450_ <aromatase>（p450_鸡外卵的外部最大的鸡毛囊（F1-F4）卵泡20小时和3小时，然后预期排卵F1。在卵泡生长的这一时期，在颗粒状的Layr中，E和T浓度保持较低，而P浓度在F2和F1卵泡中排卵前3小时。雌二醇水平最高，在卵泡（F4）卵泡的theca国际和外部，随着卵泡生长的逐渐降低。 Testosterone content of theca interna and granulosa was greater in less mature F4-F2 follicles than that found in the most mature (F1) follicle, whereas theca externa contained little T.P was quantifiable in significant amounts only in granulosa tissue, peaking in F2 and F1 follicles at 3 h before ovulation, at which time plasma levels of steroids also rose significantly. p450_ <17alpha>主要在theca国际内表达，而p450_ <AROM>在theca externa中发现的mRNA水平在此隔室中重新添加了E的模式。在颗粒组织中，这两个基因的表达非常低，在卵泡生长过程中保持不变。这些结果表明，在卵泡生长过程中，卵巢中的E和T合成至少在P450_ <17Alpha>的mRNA水平下受调节。