Glass J D, Amann R P, Nett T M
Biol Reprod. 1984 May;30(4):894-902. doi: 10.1095/biolreprod30.4.894.
This study was undertaken to evaluate the effects of season and sex on the distribution of cytosolic estradiol-17 beta receptors (E2-receptors) within multiple regions of the ovine brain and the anterior pituitary gland. Our data confirm the existence of a saturable, high-affinity receptor specific for estradiol-17 beta (E2) in the hypothalamus and anterior pituitary gland. The concentrations of E2-receptors in tissues from castrated ewes and rams killed in December (breeding season) and May ( nonbreeding season) were determined by incubating cytosols with a saturating concentration of [3H] E2. For both sexes, the anterior pituitary gland contained the highest concentration of E2-receptor. Within the brain, the highest concentrations of E2-receptor were in the hypothalamus and preoptic area (POA), and within the hypothalamus, the median eminence-infundibular stalk (ME) contained a higher concentration of E2-receptor than the anterior and posterior hypothalamus. The numbers of E2-receptors in the anterior hypothalamus and ME of ewes were 2- 3X those for rams. In ewes, there was little seasonal difference in the numbers of E2-receptors in the POA, anterior hypothalamus and ME. In rams, there was little seasonal difference in the numbers of E2-receptors in the POA and anterior hypothalamus. For both sexes, there were fewer E2-receptors in the anterior pituitary gland and posterior hypothalamus in May than in December. Thus, during the nonbreeding season, the major neuroendocrine site of action of E2 probably is within the brain, specifically in the POA, anterior hypothalamus and ME of the ewe, and in the POA and the anterior hypothalamus of the ram. These data do not support a mechanism whereby the increased sensitivity to sex steroids during the nonbreeding season is due to enhanced numbers of E2-receptors.
本研究旨在评估季节和性别对绵羊脑及垂体前叶多个区域内细胞溶质雌二醇 - 17β受体（E2受体）分布的影响。我们的数据证实，下丘脑和垂体前叶存在对雌二醇 - 17β（E2）具有特异性的可饱和、高亲和力受体。通过用饱和浓度的[3H]E2孵育细胞溶质，测定了12月（繁殖季节）和5月（非繁殖季节）处死的去势母羊和公羊组织中的E2受体浓度。对于两性而言，垂体前叶中E2受体浓度最高。在脑内，E2受体浓度最高的区域是下丘脑和视前区（POA），在下丘脑中，正中隆起 - 漏斗柄（ME）中的E2受体浓度高于下丘脑前部和后部。母羊下丘脑前部和ME中的E2受体数量是公羊的2 - 3倍。在母羊中，POA、下丘脑前部和ME中E2受体数量几乎没有季节性差异。在公羊中，POA和下丘脑前部的E2受体数量几乎没有季节性差异。对于两性而言，5月垂体前叶和下丘脑后部的E2受体比12月少。因此，在非繁殖季节，E2的主要神经内分泌作用部位可能在脑内，具体而言是母羊的POA、下丘脑前部和ME，以及公羊的POA和下丘脑前部。这些数据不支持非繁殖季节对性类固醇敏感性增加是由于E2受体数量增加的机制。
