Departamento de Psicobiología, Facultad de Psicología, Universidad Nacional de Educación a Distancia, Madrid, Spain.
Instituto de Investigaciones Biomédicas Alberto Sols, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
Cereb Cortex. 2018 Aug 1;28(8):2846-2853. doi: 10.1093/cercor/bhx163.
Androgenization in adult natal women, as in transsexual men (TM), affects brain cortical thickness and the volume of subcortical structures. In order to understand the mechanism underlying these changes we have developed an adult female rat model of androgenization. Magnetic resonance imaging and spectroscopy were used to monitor brain volume changes, white matter microstructure and ex vivo metabolic profiles over 32 days in androgenized and control subjects. Supraphysiological doses of testosterone prevents aging decrease of fractional anisotropy values, decreased general cortical volume and the relative concentrations of glutamine (Gln) and myo-Inositol (mI). An increase in the N-acetylaspartate (NAA)/mI ratio was detected d. Since mI and Gln are astrocyte markers and osmolytes, we suspect that the anabolic effects of testosterone change astrocyte osmolarity so as to extrude Mi and Gln from these cells in order to maintain osmotic homeostasis. This mechanism could explain the brain changes observed in TM and other individuals receiving androgenic anabolic steroids.
成年natal 女性的雄激素化，如同跨性别男性（TM）一样，会影响大脑皮质厚度和皮质下结构的体积。为了了解这些变化的潜在机制，我们开发了一种成年雌性大鼠的雄激素化模型。磁共振成像和光谱学被用于监测雄激素化和对照组动物在 32 天内的脑容量变化、白质微观结构和离体代谢谱。超生理剂量的睾酮可预防衰老导致的各向异性分数值降低、全脑皮质体积减少以及谷氨酰胺（Gln）和肌醇（mI）的相对浓度降低。还检测到 N-乙酰天门冬氨酸（NAA）/mI 比值增加。由于 mI 和 Gln 是星形胶质细胞的标志物和渗透调节剂，我们怀疑睾酮的合成代谢作用改变了星形胶质细胞的渗透压，从而将 Mi 和 Gln 从这些细胞中挤出，以维持渗透压的平衡。这种机制可以解释在 TM 和其他接受雄激素合成代谢类固醇的个体中观察到的大脑变化。
