Caldwell J D
Department of Pharmaceutical Sciences, North Dakota State University, Fargo, USA.
Horm Metab Res. 2001 Jan;33(1):7-9. doi: 10.1055/s-2001-12618.
We have demonstrated a high density of both radiolabeled progesterone and estradiol conjugated to bovine serum albumin binding sites in the medial preoptic area and hypothalamus. Infusions of sex hormone binding globulin into the medial preoptic area of rats increased their female sexual receptivity similarly to the effect of estradiol conjugated to bovine serum albumin, suggesting sex hormone binding globulin acts at binding sites for estradiol conjugated to bovine serum albumin. In this study sex hormone binding globulin was used to displace radiolabeled progesterone conjugated to bovine serum albumin from plasma membrane fractions from the medial preoptic area-anterior hypothalamus and medial basal hypothalamus of ovariectomized rats injected with either 5 microg estradiol benzoate or sesame oil vehicle. We found that sex hormone binding displaced radiolabeled progesterone conjugated to bovine serum albumin in both areas and that in vivo estradiol treatment greatly increased the relative displacement by sex hormone binding globulin in the medial preoptic area-anterior hypothalamus. We interpret these data as indicating the presence of sex hormone binding globulin receptors in brain plasma membranes and further suggest that endogenous steroid conditions may alter these receptors.
我们已证明，在视前内侧区和下丘脑，与牛血清白蛋白结合的放射性标记孕酮和雌二醇的结合位点密度很高。将性激素结合球蛋白注入大鼠视前内侧区，可增加其雌性性行为接受能力，这与结合牛血清白蛋白的雌二醇的作用相似，表明性激素结合球蛋白作用于结合牛血清白蛋白的雌二醇的结合位点。在本研究中，使用性激素结合球蛋白从注射了5微克苯甲酸雌二醇或芝麻油载体的去卵巢大鼠的视前内侧区-下丘脑前部和下丘脑内侧基部的质膜组分中置换与牛血清白蛋白结合的放射性标记孕酮。我们发现，性激素结合在这两个区域都能置换与牛血清白蛋白结合的放射性标记孕酮，并且在体内，雌二醇处理大大增加了视前内侧区-下丘脑前部性激素结合球蛋白的相对置换量。我们将这些数据解释为表明脑质膜中存在性激素结合球蛋白受体，并进一步表明内源性类固醇状况可能会改变这些受体。
