【作者】 陈秀明；

【导师】 常青；

【作者基本信息】 第三军医大学 ， 妇产科， 2007， 硕士

【摘要】 绝经后雌激素减少引发的围绝经期综合症、骨质疏松等疾病,严重影响了老年女性的生活质量。临床上多采用激素治疗（Hormone Therapy,HT）改善绝经女性的生活质量。HT可以缓解围绝经期综合征,减少骨质疏松及老年性痴呆的发病,改善泌尿生殖道萎缩。但美国国立卫生研究院（National Institutes of Health,NIH）进行的一项关于HT的临床研究认为这一疗法存在潜在的致病危险,长期应用影响中风、心脏病及乳腺癌的发病率。所以人们试图寻找一种新型的具有雌激素活性而不增加子宫内膜癌及乳腺癌的发病率的雌激素受体调节剂（Selective Oestrogen Receptor Modulators,SERMs）供临床选择用药。植物雌激素（Phytoestrogen,PE）异黄酮（Isoflavone,IS）的结构及生物活性与雌二醇（Estradiol,E₂）相似,能够结合并激活哺乳类动物及人类的雌激素受体（EstrogenReceptor,ER）,具有雌激素样和抗雌激素样活性,属于SERMs。长期使用可能缓解潮热、出汗等围绝经期症状,预防骨质疏松及老年性痴呆发生。但IS与ER的结合能力弱于E₂,其结合ER后表现出的雌激素活性仅为E₂的1/1000。至今对其潜在的毒副作用及使用剂量和毒性剂量仍缺乏确切了解,所以限制了它的使用。20世纪90年代初上市的异丙氧基异黄酮（ipriflvone）和1998年初美国上市的雷洛昔芬（raloxifene）作为与雌激素结构相似的骨质疏松症防治药物,在一定程度上降低了雌性激素样活性和致癌危险性,提示异黄酮结构改造可以改变其原有生物学效应。基于这种思路,四川大学华西医学中心药学部以异黄酮母环为基本分子结构在结构的不同部位以哌嗪基、甲氧基等基团引入、取代或置换改构合成了24种异黄酮类化合物。通过前期实验筛选出抑制癌细胞增殖活性最强,同时对正常的子宫内膜细胞又无明显促增殖作用的化合物（F11）。本实验是将该化合物用于去卵巢大鼠动物模型,观察其对大鼠血脂代谢和骨代谢的生物学效应,为开发新型SERMs提供理论依据。本实验首先成功构建去卵巢大鼠动物模型,通过腹腔注射方法将该化合物（F11）用于该模型,连续给药10周后活杀大鼠,取血清及大鼠股骨标本进行检测,观察其对去卵巢大鼠血脂代谢和骨代谢生物学效应的影响。主要的结果及结论如下:1.与OVX组比较,F11三个剂量组股骨的最大载荷量增加（P＞0.05）;弹性载荷和挠度强度显著增加（P＜0.05）;弹性模量、定压缩强度、屈服强度及抗压强度显著降低（P＜0.05）:高剂量组弯曲强度明显增加（P＜0.05）,F11中低剂量弯曲强度（P＞0.05）。提示低剂量F11即可对股骨力学性能影响,有剂量依从关系。2.与OVX组相比,F11各组骨小梁粗大,无断裂,间隙正常,三维网架结构正常,骨小梁的拱桥形结构呈圆形、卵圆形或梭形,皮质骨略增厚。F11高剂量组更接近SHAM组。提示F11可能减少骨量的丢失,改善骨小梁结构,增加小梁骨密度,同时可能改善皮质骨结构,增强骨应力,维持骨吸收和骨形成的动态平衡。3.与OVX组相比,F11各组血钙浓度增加无统计学意义（P＞0.05）,血清碱性磷酸酶和骨钙素显著降低（P＜0.05）,推测F11可能抑制骨吸收,促进成骨细胞活性。4.与OVX组相比,F11低剂量组总胆固醇TC、HDL和LDL无显著（P＞0.05）,甘油三脂（TG）有显著差异（P＜0.05）,对LDL无明显影响;F11中剂量组总胆固醇和HDL及LDL轻微降低（P＞0.05）,显著增加甘油三脂（P＜0.05）;F11高剂量组总胆固醇和HDL及LDL明显降低（P＜0.05）,甘油三脂显著增加（P＜0.05）。FⅡ可影响血脂,存在剂量依存性关系。5.F11可以提高大鼠子宫湿重/体重比值;刺激大鼠阴道上皮成熟;改善去卵巢大鼠阴道和子宫萎缩,其生物学效应呈剂量依赖关系,提示F11可能具有雌激素生物学效应。更多还原

【Abstract】 Background and ObjectiveThe decrease of Estrogen after menopause is connected with perimenopausal syndrome and osteoporosis etc,which affected the old-age-women’ quality of life.The clinical therapy with Hormone（HT） can relieve the perimenopausal syndrome and has positive therapeutic effect on osteoporosis and Alzheimer’s disease（AZ）.It also may improve the genitourinary tract atrophy.But the conclusion of National Institutes of Health（NIH） from their five years study increases the caring and discussion about HT.This kind of therapy may increase the risk of disease.Long term of HT may influence the incidence rate of theoplegia, cardiopathy and breast cancer.So it’s necessary to find a novel selective estrogen receptor modulators（SERMs） which not only has the activity of can protect estrogen but also doesn’t improve the morbility of endometrial carcinoma.Isoflavone（IS） belongs to phytoestrogen（PE） family,and it’s structure and bioactivity is similar to estradiol（E₂）.It’s a kind of SERMs and can active and bind with estrogen receptors of mammalian animals and human.It has estrogen-like and antiestrogen-like activities.Long term of it may relieve menopause symptoms such as hot flush and sweat, prevention osteoporosis.Meanwhile,it doesn’t raise the possibility of Alzheimer’s disease （AZ）.The ability of combination to receptor of estrogen of IS is less than E₂,while_w it’s bioactivity after combination with receptor is 1/1000 of E₂.By now,it’s poisonous and side effect and its dosage are not understood clearly,which limits its application.In the early of 1990 and 1998,ipriflvone（IP） and raloxifene,as a medicine to osteoporosis with similar construction to estrogen,decreased the estrogen-like activity and incidence risk of cancer.It implied that the IP’s biological effect can be changed after its structure has been changed.The pharmacy department of HUA XI medical centre of Si Chuan University added different active groups such as piperazine group,methoxy group to different parts of IS parent ring and synthesized 24 structure-changed isoflavone compounds. Based on the ability of inhibition the proliferation of cancer cells and endometria,the reconstructed isoflavone（F11） appears to be most powerful one.We applied F11 to ovariectomized rat and observed its effect on the bone metabolism and serum-lipid metabolism,in order to provide theoretical proof to the exploitation of new SERMs.MethodFirstly,we constructed the ovariectomized rat successfully.F11 was injected into the abdomen and successively administrated for 10 weeks.The rats were sacrificed by femoral artery blood letting.The serum and femoral bone were collected to detect the level of total cholesterol（TC）,triglyeride（TG）,lipoprotein（LDL/HDL）,Osteocalcin（OC）,Alkaline Phosphatase（ALPase） and blood calculus;the vitodynamics and histomorphology of femoral bone were also been observed.Result and Conclusion1.F11 could increase the maximum load of femoral bone.Compared to the OVX group,F11 enhanced elastic load and flexivity intensity obviously,and cut down the elastic modulus,compressive strength,yield strength and crushing strength significantly（P＜0.05）. Low and moderate dose F11 couldn’t improve the bending strength of femoral bone as much as high dose F11 did,which suggested even low dose F11 could affect the mechanics performance of femoral bone and this effect is connected with the dosage.2.Compared with OVX group,F11 groups had more regular bone layers-like structure. The bone trabecula was thicker and less broken.Three dimension frame was normal.The arch-bridge-like structure of bone trabecula appeared round,orbicular-ovate or fusiform shape.The high-dose group of F11 was more closed to sham group.These suggested that F11 could decrease the loss of bone mass,improve the structure and intensity of bone trabecula and os integumentale,enhance bone stress,maintain the dynamic equilibrium between bone resorption and bone formation.3.The level of blood calculus was higher in F11 groups than that in control group,The level of ALPase and OC in F11 groups was obviously lower than that in control group, which may caused by promoted intestinal absorption.It suggested that F11 may prevent osteoporosis by promoting the activity of osteoblast and inhibiting bone resorption.4.Low dose F11 increased the TC and HDL slightly and had not much effect on LDL, increase TG level significantly.Moderate dose F11 lowered the level of TC,HDL and LDL slightly,increase TG level significantly.High dose F11 obviously lowered the level of TC, HDL and LDL,increase TG level significantly.All these meant that this effect was dose-dependent manner5.F11 improved the rate of uterus wet weight/body weight;stimulated the mature of vagina epithelium;ameliorated the vagina and uterus atrophia in ovariectomized rat.Its biological effect was a dose-dependent manner and this meant it may have the estrogen biological effect.更多还原