Alzheimer’s disease: the impact of age-related changes in reproductive hormones

Receptors for hormones of the hypothalamic-pituitary-gonadal (HPG) axis that regulate reproductive function are expressed throughout the brain, and in particular the limbic system. The most studied of these hormones, the sex steroids, contain receptors throughout the brain, and numerous estrogenic, progestrogenic and androgenic effects have been reported in the brain related to development, maintenance and cognitive functions. Although less studied, receptors for gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and activins also are found throughout the limbic system on a number of cell types, and they too transduce signals from circulating hormones as demonstrated by their multiple effects on the growth, development, maintenance and function of the brain. This review highlights the point that because of the feedback loops within the HPG axis, it is difficult to ascribe structural and functional changes during development, adulthood and senescence to a single HPG hormone, since a change in the concentration of any hormone in the axis will modulate hormone concentrations and/or receptor expression patterns for all other members of the axis. The most studied of these situations is the change in serum and neuronal concentrations of HPG hormones associated with menopause/andropause. Dysregulation of the HPG axis at this time results in increases in the concentrations of serum GnRH, gonadotropins and activins, decreases in the serum concentrations of sex steroid and inhibin, and increases in GnRH and LH receptor expression. Such changes would result in significantly altered neuronal signaling, with the final result being that there is i.e. increased neuronal GnRH, LH and activin signaling, but decreased sex steroid signaling. Therefore, loss of cognitive function during senescence, typically ascribed to sex steroids, may also result from increased signaling via GnRH, LH or activin receptors. Future studies will be required to differentiate which hormones of the HPG axis regulate/maintain cognitive function. This introductory review highlights the importance of the identification of HPG hormone neuronal receptors and the potential of serum HPG hormones to transduce signals to regulate brain structure and function during development and adult life.     

经产大鼠肝郁气滞型乳腺增生病模型血清激素变化观察

目的观察经产大鼠乳腺增生病病证结合模型血清激素变化。方法将20只雌性经产SD大鼠分为正常组、模型组,模型组大鼠隔2日肌肉注射苯甲酸雌二醇注射液1.0mg/kg,连续10次,之后每日肌肉注射黄体酮5.0mg/kg,连续5日,在整个造模过程中隔日一次将其装入特制的束缚笼中束缚固定过夜,共15次。在末次注射黄体酮次日禁食12h,速眠新麻醉股动脉取血备检。结果模型组大鼠血清泌乳素、雌二醇升高,孕酮降低。结论经产大鼠肝郁气滞型乳腺增生病模型血清激素变化以血清雌二醇升高为主要特征。     

乳腺增生动物模型的建立及健乳灵对其治疗效果的观察

将大鼠随机分成正常对照,模型对照和治疗组,用雌二醇和孕酮诱导大鼠发生乳腺增生,观察乳头高度、乳腺组织结构、测定体内生殖激素水平。结果：模型对照动物液中的垂体促乳素,促卵泡素和雌二醇的浓度显著高于正常对照,促黄体素和孕酮则明显降低;模型对照动物的第２、３对乳头高度显著增高;在治疗组中,结果显示健乳灵在一定程度上可以调整体内垂体－性腺的激素分泌活动;并对乳腺增生病大鼠的乳腺组织有明显的改良作用     

脱水穿心莲内脂丁二酸单酯钠盐的抗早孕机理初探

采用放射免疫分析测定技术,研究了脱水穿心莲内酯丁二酸单酯钠盐制剂对体外培养的人绒毛组织激素分泌的影响,并应用透射电镜技术,从超微结构的水平上观察分析了穿心莲制剂组织特异性细胞毒效应,发现这种穿心莲制剂能特异性破坏绒毛合体滋养层细胞结构,包括蛋白质的合成系统,使hCG的合成受影响。用放射免疫法测定培养液中的hCG,以确定该激素的合成与分泌状态,结果发现,穿心莲制剂处理的实验组,hCG的合成和分泌明显受阻,与对照组差异显著。超微结构观察表明,穿心莲制剂的细胞毒作用是组织特异性和剂量依赖性的,特异地作用于绒毛的合体滋养层细胞而对细胞滋养层及间质组织均无损伤。     

高效液相色谱法定性测定牦牛被毛和血浆中的类固醇激素

本试验在7—8月,牦牛发情季节里,对8头麦洼母牦牛进行采血,采毛,并对这些样品中六种类固醇激素进行了高效液相色谱(HPLC)定性测定。结果显示在被毛和血浆中HPLC分离曲线相似,二者都存在E_1,E_2、E_3、T、P_4和P_3六种成分,另外还有七种未知成分也相同。结果说明被毛和血浆中含有相似的类固醇激素类型,同时也说明了类固醇激素经被毛降解也是其代谢途径之一。为探索被毛中类固醇激素的含量和血浆中类固醇激素含量的相关性提供了可能,为家畜妊诊方法的简化提供了可能。     

外源激素(HCG)对母鸡产蛋水平及其蛋品质影响的试验研究

经四年试验研究,利用二龄母鸡进行外源激素(HCG)处理结果,试验群较对照群可提高产蛋水平25.9-29.3%;同时蛋只枚重也有明显增加.蛋只增重范围0.7-3.3克;平均每枚增重为1.1克.投资与收益相比,为1∶6.0-1∶9.6     

2，4-D和6-BA对唐古特大黄愈伤组织诱导的影响

实验选用唐古特大黄(Rheum tanguticumMaxim.ex Regel.)种子萌发的无菌苗为外植体进行离体培养.结果表明,2mg/L的2,4-D最有利于愈伤组织的形成,但更高浓度的2,4-D会影响诱导效果;1mg/L的6-BA有利于愈伤组织的快速诱导,但单独的6-BA无诱导作用.     

杉木优树大量繁殖技术的研究

以１８年生杉木优树嫁接苗（一年生）为外植体进行离体培养,茎段的最高分化率为６９％,侧芽的最高分化率为４０％。以茎段为外植体,在改良的ＭＳ（氮元素减半）＋ＢＡＰ２．０ｍｇ／Ｌ＋ＩＢＡ１．０ｍｇ／Ｌ的培养基上,平均每个茎段可诱导不定芽３～４个。在继代培养中,以改良的ＧＤ培养基加高浓度的ＢＡＰ６．７ｍｇ／Ｌ,平均每个茎段可诱导不定芽１１～１３个,然后在ＭＳ培养基上生长;在继代培养中激素浓度一般由低到高,再由高到低的循环,可以明显提高繁殖率。在生根培养中,以ＭＳ培养基（氮元素减半）加ＩＢＡ１．５ｍｇ／Ｌ,根的诱导率在４４％。