McCormick Cheryl M, Linkroum William, Sallinen Bethany J, Miller Nicholas W
Neuroscience Program, Department of Psychology, Bates College, Lewiston, Maine 04240, USA.
Stress. 2002 Dec;5(4):235-47. doi: 10.1080/1025389021000061165.
Sex differences in hypothalamic-pituitary-adrenal (HPA) function were examined in gonadectomized male and female rats given equivalent sex hormone replacement regimens either using subcutaneous silastic implants (Experiment 1) or cannula implants in the medial preoptic area (MPOA) (Experiment 2) containing either dihydrotestosterone (DHT), testosterone propionate (TP), estradiol benzoate (EB), or left empty (control). Plasma was obtained before and after 20 min of restraint stress to determine plasma ACTH, corticosterone, and CBG levels as measures of HPA function. Consistent with the literature, androgens decreased, and estrogen increased these measures of HPA function, although peripheral implants were more effective than MPOA implants. Gonadectomy and sex hormone treatment did not eliminate sex differences; overall, females had higher levels than males on measures of HPA function. Analyses of variance (ANOVA) indicated interactions of sex and sex hormone treatment on CBG levels and post-stress corticosterone levels in Expt. 1. The results suggest that sexual dimorphisms influence HPA function even when males and females are given equivalent physiological doses of gonadal steroids, and that the relevant sexual dimorphisms involve both the periphery and the CNS.
在接受性腺切除的雄性和雌性大鼠中，研究了下丘脑-垂体-肾上腺（HPA）功能的性别差异。这些大鼠接受了等效的性激素替代方案，采用皮下硅橡胶植入物（实验1）或视前内侧区（MPOA）的套管植入物（实验2），植入物中含有二氢睾酮（DHT）、丙酸睾酮（TP）、苯甲酸雌二醇（EB）或为空（对照）。在束缚应激20分钟前后采集血浆，以测定血浆促肾上腺皮质激素（ACTH）、皮质酮和皮质类固醇结合球蛋白（CBG）水平，作为HPA功能的指标。与文献一致，雄激素降低，雌激素增加这些HPA功能指标，尽管外周植入物比MPOA植入物更有效。性腺切除和性激素治疗并未消除性别差异；总体而言，在HPA功能指标上，雌性水平高于雄性。方差分析（ANOVA）表明，在实验1中，性别和性激素治疗对CBG水平和应激后皮质酮水平存在交互作用。结果表明，即使给雄性和雌性给予等效生理剂量的性腺类固醇，性二态性仍会影响HPA功能，且相关的性二态性涉及外周和中枢神经系统。
