Aromatase and 5 beta-reductase activity in cultures of developing zebra finch brain: an investigation of sex and regional differences.
Aromatase and 5 beta-reductase activity in cultures of developing zebra finch brain: an investigation of sex and regional differences.
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DOI：
10.1002/neu.480270210
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发表时间：
1995-06
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影响因子：
--
通讯作者：
J. Wade;B. Schlinger;A. Arnold
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文献类型：
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作者：
J. Wade;B. Schlinger;A. Arnold
雌性斑马雀幼鸟接受雌激素处理后，歌唱行为和参与歌唱控制的端脑脑区的雄性发育。然而，对男性进行早期雌激素治疗也会阻止男性交配行为的发展，这可能是由间脑区域控制的。为了确定雌激素作用的差异是否与性别和雄激素代谢的地区差异(雌激素合成或雄激素失活)有关，我们测量了不同条件下幼年斑雀的端脑、间脑和小脑的分离细胞培养物中芳香化酶和5β-还原酶的活性。来自这三个大脑区域的培养物都表现出高水平的芳香酶和5β-还原酶活性。比较端脑和间脑培养物芳香化酶的活性和动力学表明，端脑培养物比间脑培养物更有效地将雄激素转化为雌激素，这可能在雌激素在两个脑区的不同作用中起重要作用。然而，在端脑和间脑培养中，芳香酶和5-β-还原酶的活性在性别之间都没有显著差异。因此，性别之间的比较不支持这样的观点，即羽化后芳香酶或5β-还原酶活性的差异可以解释鸣叫和交配系统的性别分化模式。
Estrogen treatment of hatchling female zebra finches causes the masculine development of singing behavior and of the telencephalic brain regions involved in the control of song. However, early estrogen treatment of males also blocks masculine development of copulatory behavior, presumably controlled by diencephalic regions. In an effort to determine whether the differences in estrogen action are related to sex and regional differences in androgen metabolism (estrogen synthesis or androgen inactivation), we measured aromatase and 5 beta-reductase activity in dissociated-cell cultures made separately from the telencephalon, diencephalon, and also cerebellum of hatchling zebra finches under a variety of conditions. Cultures from all three brain regions express high levels of aromatase and 5 beta-reductase activity. Comparisons between telencephalic and diencephalic cultures of the activity and kinetics of aromatase suggest that the telencephalic cultures convert androgen to estrogen more efficiently than diencephalic cultures, which might be important in the differential action of estrogen in the two brain regions. However, the activity of neither aromatase nor 5 beta-reductase was significantly different between the sexes in either telencephalic or diencephalic cultures. Thus, comparisons between the sexes do not support the idea that differences in posthatching aromatase or 5 beta-reductase activity account for the pattern of sexual differentiation of the song and copulatory systems.