7,12-二甲基苯蒽诱发大鼠乳腺癌的激素依赖性及孕、雌激素受体状况

用DMBA诱发雌性S-D大鼠乳腺癌。给50日龄大鼠每只胃饲20mg DMBA(溶于芝麻油中),一个月后第二次喂药;二次喂药组的发病率高于一次喂药组。从病理形态观察,DMBA诱发乳腺癌以乳腺小叶浸润癌和导管浸润癌为主。87%癌组织??匀浆的ER值大于10fmol/mg蛋白。56%的PR大于10fmol/mg蛋白。切除大鼠双侧卵巢观察此乳腺癌对激素的依赖性表明:65%对卵巢切除有反应性,肿瘤明显缩小。同鼠不同肿块间的ER值、病理形态近似。大鼠乳腺癌ER的特异性与人乳癌相似。试验结果表明:此工作及提供的动物实验模型为进一步研究乳腺癌内分泌治疗的机理和发展新的抗雌激素药物打下基础。     

Does neonatal androgen modulate uptake and retention of 3H-estradiol in gonadotrophs and lactotrophs?

Summary Castrated adult male and female and androgenized female rats (AS rats) were injected i.v. with ³H-estradiol (E₂). Nuclear uptake and retention of the ³H-steroid was examined in pituitary luteinizing hormone (LH) and prolactin (PRL) cells by the combined techniques of autoradiography and immunocytochemistry. About 80% of PRL cells were found to concentrate the radioactive steroid compound in all experimental groups, while 89%, 82% and 68% of LH cells were found to be labeled in AS rats, normal female and male rats, respectively. This suggests that there are subpopulations of LH or PRL cells that contain no or, if any, small numbers of E₂ receptor. Statistical analysis revealed that PRL cells take up more radioactivity than LH cells in male rats, while there is no significant difference between female and AS rats. Variations in E₂ uptake (coefficient of variation) was higher in LH cells than in PRL cells in male rats and in AS rats. In females, on the contrary, coefficient of variation was larger in PRL cells. Thus the characteristics of nuclear uptake and retention of estradiol in LH and PRL cells appear to be modulated in part by neonatal androgen since the pattern found in AS rats is different than that found in normal male and female rats.     

鸡输卵管胞液中雌激素受体的性质研究

以乙酚(DES)刺激未成年的雌鸡,输卵管增长到0.6到1.0克,胞液中含有的雌激素受体为0.082微微克分子/毫克蛋白,此种受体表现有以下的特性。 1.专一地结合雌性激素。以雌二醇作配基时平衡解离常数是0.25×10~(-9)M~(-1);在输卵管胞液中该受体的结合位点是1356/细胞。 2.硫酸铵沉淀胞液中的雌激素受体已转变成为团聚状态,如在硫酸铵沉淀的过程中有钼酸钠存在则能明显地减少团聚,因此钼酸钠有防止胞液中受体团聚的作用。 3.胞液中雌激素受体进行DEAE—葡聚糖凝胶柱层析,不论有或无钼酸钠存在,均表现为一个单一的峰。     

Time Course and Localization of the Effects of Estrogen on Glutamic Acid Decarboxylase Activity1

Abstract: Two approaches were used in an attempt to characterize the effect of estrogen on glutamic acid decarboxylase (GAD) [EC 4.1.1.15] activity in ovariectomized rats. In the first experiment, estradiol-17β (E₂) was unilaterally implanted in one of five different brain areas. After 3 days of estrogen exposure, the animals were sacrificed, and GAD activity in the substantia nigra (SN) and ventral tegmental region (VTR) was measured. Estrogen implanted into the preoptic area and the ventromedial nucleus was ineffective, as were implants of cholesterol, regardless of implant site. However, GAD activity was decreased in the SN when E₂ was implanted into the caudate nucleus or amygdala and in the VTR when implanted into the nucleus accumbens septi. Furthermore, this decrease in GAD activity occurred only in the implanted side. In the second experiment, the time course of changes in GAD activity was measured in ovariectomized rats given a single systemic injection of either 8μg estradiol benzoate (EB) or oil. Rats were sacrificed at 0, 12, 29, or 53 h postinjection. It was found that GAD activity in the SN was maximally suppressed 29 h after EB, whereas decreased GAD activity in the VTR was apparent 12 h after EB but had returned to normal by 29 h. Oil injections had no significant effect on GAD activity. These results suggest that there may be two separate and distinct γ-aminobutyric acid pathways, which are differentially responsive to estrogen.     

Estrogen interaction with the anterior pituitary of female rats differential cytosol binding, nuclear translocation and stimulation of RNA synthesis by 17β-estradiol and tamoxifen

The interaction of tamoxifen (trans-1-(p-β-dimethylaminoethoxyphenyl)-1,2-diphenylbut-1-ene) with the cytosol estrogen receptor of the anterior pituitary of female rats was studied. No differences were recorded between incubations of cytosol samples with 17β-[³H]estradiol performed in the presence or absence of unlabeled 17β-estradiol and tamoxifen, respectively, thus suggesting that these interactions were at common receptor sites and excluding possible cooperative interactions. Competition experiments and Scatchard plot analysis of saturation experiments add further evidence for common receptor sites. A dissociation constant for tamoxifen of K_d = 2 nM was recorded. Tamoxifen was found to be bound to a moiety sedimenting in the 4–5 S region, on a 6–24% linear sucrose density gradient at low salt concentrations, whereas 17β-estradiol sedimented in the 8–9 S area. These data suggest possible conformational changes of the receptor in the presence of tamoxifen. Furthermore, nuclear estrogen receptor levels remained elevated for at least 80 h after the application of tamoxifen alone or in a combination with 17β-estradiol, and a concomitant inhibition of cytosol receptor replenishment was noted. Tamoxifen and 17β-estradiol, respectively, were found to stimulate progesterone receptor levels when applied through 5 days. Tamoxifen plus 17β-estradiol administration elevated progesterone receptor contents above those found for each of the two compounds alone. On the other hand, tamoxifen enhanced the 17β-estradiol-induced prolactin serum levels, but did not stimulate prolactin serum levels by itself. These data combine to suggest that tamoxifen interacts with common estrogen receptor sites at the rat anterior pituitary.     

GSTs同工酶基因在乳腺癌中的扩增与基因的表达

采用ＤＮＡ和ＲＮＡ的斑点杂交分析方法,对３２例乳腺癌和相应的癌旁正常组织中ＧＳＴ－π、ＧＳＴ－α和ＧＳＴ－μ基因的ＤＮＡ扩增和ＲＮＡ转录表达情况进行研究,发现ＧＳＴ－π在乳腺癌中存在基因扩增和明显的ｍＲＮＡ表达升高,ＧＳＴ－π基因表达调控主要在转录水平进行的;ＧＳＴ－α和ＧＳＴ－μ在乳腺癌中表达水平较低,但仍可见α和μ类ＧＳＴ同工酶ｍＲＮＡ转录在肿瘤和正常组织中发生了较大的变化。结合乳腺癌中雌激素受体（ＥＲ）表达情况还发现ＧＳＴ－π表达水平与ＥＲ的表达存在负相关性。     

三苯氧胺和雌二醇对大鼠子宫雌激素受体的竞争性结合作用

利用改进的葡聚糖活性炭饱和分析法（ＤＣＣ法）,对卵巢切除大鼠注射雌二醇（Ｅ组）或同时注射雌二醇和三苯氧胺（Ｅ＋Ｔ组）后６ｈ至６４ｄ,进行子宫ＥＲ含量测定,发现,Ｅ＋Ｔ组比Ｅ组的ＥＲ值小并且增加缓慢;Ｅ组的ＥＲ值在注射后３０ｄ达到最大值而且数值超过对照组（Ｃ组）。计算机曲线拟合Ｅ组或Ｅ＋Ｔ组与Ｃ组的ＥＲ比值求得：Ｅ组开始注射雌二醇时ＥＲ水平为Ｃ组的２．０３３倍,即＝２．０３３,恢复过程的时间常数τ＇为５１．５５ｄ,３￣Ｈ－雌二醇与ＥＲ结合过程的时间常数τ为１３．０ｄ;Ｅ＋Ｔ组的＝１．３１５,τ＇＝３８．７６ｄ,τ＝２１．５５ｄ,说明同时给予三苯氧胺和雌二醇情况下,三苯氧胺有抑制雌二醇诱导ＥＲ水平升高的作用,并减缓３￣Ｈ－雌二醇与ＥＲ的结合过程。另外,还求得Ｅ＋Ｔ组中三苯氧胺和ＥＲ和结合率约占４３．７％,表明三苯氧胺与雌二醇对ＥＲ有竞争性结合作用。     

胃肠肿瘤雌、孕激素受体与癌胚抗原的免疫组织化学研究

利用酶联亲和组织化学法和ＡＢＣ免疫组织化学法进行８８例胃肠肿瘤的雌激素受体（ＥＲ）、孕激素受体（ＰＲ）和癌胚抗原（ＣＥＡ）的检测．结果表明：ＥＲ、ＰＲ、ＣＥＡ的阳性率分别为３７．５％（３３／８８）、２７．３（２４／８８）、８８．６４（７８／８８）。ＥＲ、ＰＲ的阳性率与肿瘤的组织学分类及病理分级有关。ＣＥＡ仅与病理分级有关。且与性激素受体水平呈负相关。因此,性激素受体与ＣＥＡ的表达提供了肿瘤组织不同的生物学特征,同时检则ＥＲ、ＰＲ及ＣＥＡ水平对内分泌治疗及判断预后更有价值。     

Up-regulation of nitric oxide synthase by estradiol in human aorticendothelial cells

We have examined the effects of sex hormones on calcium-dependent NO production and protein levels of NO synthase in cultured human aortic endothelial cells, which were treated with various doses of 17β-estradiol and testosterone for 8–48 h. Treatment with 17β-estradiol enhanced calcium-dependent NO production, but testosterone had exerted no effect. Western blot using monoclonal anti-human endothelial NO synthase antibody clarified that increased NO production by 17β-estradiol treatment was accompanied by increased NO synthase protein. Our results provide evidence that human endothelial NO synthase can be regulated by estrogens.