Nance D M, Gorski R A
Pharmacol Biochem Behav. 1975;3(1 Suppl):155-62.
Androgens produce a permanent organizational effect on the brain of rats during a postnatal period of sexual differentiation. In male rats, this process occurs as a consequence of the endogenous release of androgens; however, exposing female rats to exogenous androgens during this critical period initiates the same process, such that early exposure to androgens results in a dose-dependent increase in body weight. Sex-specific gonadal hormones further modulate this basic organizational difference in that androgens and estrogens have facilitatory and inhibitory effects, respectively, on the regulation of food intake (FI) and body weight (BWt). While the biochemical or anatomical basis of this sexual dimorphism in energy regulation has not been defined, the data presented here support the idea of a functional sex difference in the hypothalamic regulation of FI and BWt. In general, the same kinds of behavioral tests which differentiate between normal animals and rats with lesions of the ventromedial hypothalamus (VMH) or lateral hypothalamus (LH) also differentiate between male and female rats. Male rats respond to regulatory challenges more similar to VMH lesioned animals than do female rats. In addition, it has been shown that the VMH may be a primary neural site for the organizational effects of androgens on the brain. Based upon these data and the fact that rats show a sex difference in exactly those regulatory behaviors which are presumably controlled by the VMH, a model is proposed to account for sex differences in energy regulation.
雄激素在出生后的性分化期对大鼠大脑产生永久性的组织效应。在雄性大鼠中，这个过程是雄激素内源性释放的结果；然而，在这个关键时期让雌性大鼠接触外源性雄激素会启动相同的过程，因此早期接触雄激素会导致体重呈剂量依赖性增加。性别特异性的性腺激素进一步调节这种基本的组织差异，因为雄激素和雌激素分别对食物摄入量（FI）和体重（BWt）的调节具有促进和抑制作用。虽然能量调节中这种性别二态性的生化或解剖学基础尚未明确，但此处呈现的数据支持下丘脑对FI和BWt调节存在功能性性别差异的观点。一般来说，用于区分正常动物与腹内侧下丘脑（VMH）或外侧下丘脑（LH）损伤大鼠的相同类型行为测试，也能区分雄性和雌性大鼠。与雌性大鼠相比，雄性大鼠对调节挑战的反应更类似于VMH损伤的动物。此外，研究表明VMH可能是雄激素对大脑组织效应的主要神经位点。基于这些数据以及大鼠在那些可能由VMH控制的调节行为中表现出性别差异这一事实，提出了一个模型来解释能量调节中的性别差异。
