Henry C, Arsaut J, Arnauld E, Demotes-Mainard J
INSERM U-394, 'Neurobiol ogie Intégrative', Domaine de Carreire, Bordeaux, France.
Neurosci Lett. 1996 Sep 27;216(2):141-5.
Prenatal stress in rats has been found to alter the sexual dimorphism of brain structures and the sexual behavior of male offspring, pointing to an impaired masculinization of the brain during the perinatal period of brain sexual differentiation. Masculinization of the brain depends on the presence during this critical period of three main elements: adequate levels of testosterone, aromatase activity (locally converting testosterone to estradiol), and brain estrogen receptor (ER) density. In the present study, we measured by reverse transcription-polymerase chain reaction (RT-PCR) the levels of ER messenger RNA (mRNA) expression in the hypothalamus of either prenatally-stressed or control male rats at postnatal (P) days 3, 12 and 90. During the early postnatal period (P3), hypothalamic ER mRNA expression was higher in prenatally stressed male rats (6.12 +/- 0.37) than in controls (4.51 +/- 0.55) (P = 0.015). This difference was not, however, found at a later developmental stage (P12, 5.39 +/- 0.65 versus 5.39 +/- 0.47) or in adult animals (P90, 6.79 +/- 1.55 versus 7.07 +/- 1.11). This transient elevation of hypothalamic ER mRNA expression resembles the developmental profile of ER mRNA in females. These observations support the idea that androgens play a pivotal role in the demasculinization process, and suggest that testosterone production or aromatization is reduced in prenatally-stressed males during the perinatal period of sexual differentiation, leading to a transient upregulation of unstimulated estrogen receptors.
研究发现，大鼠孕期应激会改变脑结构的性二态性以及雄性后代的性行为，这表明在脑性分化的围产期，大脑男性化过程受损。大脑男性化取决于这一关键时期三个主要因素的存在：足够水平的睾酮、芳香化酶活性（将睾酮局部转化为雌二醇）以及脑雌激素受体（ER）密度。在本研究中，我们通过逆转录聚合酶链反应（RT-PCR）测量了出生后（P）第3天、12天和90天的产前应激雄性大鼠或对照雄性大鼠下丘脑ER信使核糖核酸（mRNA）的表达水平。在出生后早期（P3），产前应激雄性大鼠下丘脑ER mRNA表达水平（6.12±0.37）高于对照组（4.51±0.55）（P = 0.015）。然而，在发育后期（P12，5.39±0.65对5.39±0.47）或成年动物中（P90，6.79±1.55对7.07±1.11）未发现这种差异。下丘脑ER mRNA表达的这种短暂升高类似于雌性动物中ER mRNA的发育情况。这些观察结果支持雄激素在去男性化过程中起关键作用的观点，并表明在产前应激的雄性大鼠性分化的围产期，睾酮生成或芳香化作用降低，导致未受刺激的雌激素受体短暂上调。
