睾酮对去睾丸家兔骨密度及血清钙磷的影响

目的:观察去睾丸和睾酮补充对雄兔骨密度和血清钙、镁、磷的影响.方法:周龄相同的雄性新西兰白兔随机分成对照组、去睾丸组和睾酮补充组(去睾丸后肌注十一酸睾酮).同等条件下饲养20周后测量各组兔全身骨密度、腰椎骨密度、股骨颈骨密度,并检测血清总睾酮(TT)、雌二醇(E2),脱氢表雄酮(DHEA)水平以及血清钙(Ca2 )、游离钙([Ca2 ]i)镁(Mg2 )、磷(P)和碱性磷酸酶(AKP)浓度.结果:去睾丸组血清TT水平明显下降(P<0.01),睾酮补充组血清TT水平升高接近对照组(P>0.05).去睾丸组血清E2和E2/TT比明显高于对照组(P<0.01),睾酮补充组血清E2和E2/TT下降,接近对照组水平(P均>0.05).与对照组相比,去睾丸组血清Ca2 、[Ca2 ]i、Mg2 以及AKP浓度明显升高(P均<0.01),睾酮补充组血清Ca2 、[Ca2 ]i、Mg2 以及AKP浓度较去睾丸组低,接近对照组水平(P>0.05).股骨颈骨密度在去睾丸组明显低于对照组和睾酮补充组(P<0.01),而后两组无差别(P>0.05).结论:去睾丸后雄兔血清TT明显下降,E2和E2/TT比以及Ca2 、[Ca2 ]i、Mg2 和AKP浓度明显升高,骨密度显著下降,睾酮补充使上述异常明显改善.     

睾酮对雄兔hs-CRP、MMP-9、HO-1、APN和动脉粥样硬化斑块稳定性的影响

目的探讨睾酮对雄兔血高敏C反应蛋白（hs-CRP）、基质金属蛋白酶-9（MMP-9）、血红素氧化酶-1（HO-1）、脂联素（APN）和动脉粥样硬化斑块稳定性的影响。方法将66只雄性新西兰纯种兔随机分为4组,其中正常对照组10只（A组）、喂以普通饲料;假去势＋球囊损伤颈动脉组16只（B组）、去势＋球囊损伤颈动脉＋生理剂量睾酮（6mg/（kg.2周））肌注组16只（C组）、去势＋球囊损伤颈动脉＋生理盐水肌注组24只（D组）均喂以高脂饲料。在实验第8周随机抽取处死部分动物,观察颈动脉病变的形态特征,抽血测睾酮、hs-CRP、MMP-9、HO-1、APN水平。结果D组兔血睾酮水平显著降低;B,C组较D组兔血hs-CRP、MMP-9水平显著降低,HO-1、APN水平显著升高;且B,C组较D组兔动脉粥样斑块的面积和内-中膜厚度（IMT）显著减小,斑块纤维帽增厚、胶原含量明显增加。结论生理剂量睾酮可以影响雄兔血hs-CRP、MMP-9、HO-1、APN水平,并能调节动脉粥样硬化斑块进展与斑块的稳定性。     

雄激素对成年雄性斑胸草雀前脑高级发声中枢-弓状皮质栎核通路长时程压抑的影响

雄激素可通过调控鸣唱控制系统改变鸣禽的鸣唱行为。本研究以成年雄性斑胸草雀为实验动物,采用在体电生理实验方法,观察雄激素对高级发声中枢(high vocal center,HVC)-弓状皮质栎核(robust nucleus of the arcopallium,RA)通路突触可塑性的影响,以期阐明雄激素对成年鸣禽鸣唱稳定性维持的神经生理机制。将实验动物分为对照组、去势组与去势+埋植睾酮组,分别记录高频刺激(400 Hz,2 s)HVC后,HVC-RA通路长时程压抑(long-term depression,LTD)的变化以及双脉冲易化效应。结果显示,高频刺激HVC,在对照组可以记录到LTD现象;去势组中仅有短时程压抑(short-term depression,STD)现象;去势+埋植睾酮组中LTD现象则恢复。双脉冲易化现象在去势组不明显,而对照组和去势+埋植睾酮组易化率明显高于去势组。以上结果提示,雄激素可能通过影响成年雄性斑胸草雀HVC-RA通路的LTD水平来维持鸣曲稳定性,并对该通路的短时程突触可塑性有一定的调节作用。     

肠球菌WZM05对高胆固醇血症小鼠载脂蛋白的影响

目的探讨肠球菌WZM05对高胆固醇血症小鼠血清学指标及高胆固醇血症形成的影响。方法采用灌胃法建立小鼠高胆固醇血症模型及肠球菌实验组（10^6、10^8、10^9CFU／m1）,实验40d后,进行血清血脂水平检测及载脂蛋白A1（apoAI）、载脂蛋白B（apoB）测定。结果肠球菌组的血清总胆固醇明显降低,高密度脂蛋白明显升高（P〈0．01）,血清apoAI升高及apoB降低（P〈0．05）。结论肠球菌WZM05具有降脂、调脂作用。     

去势对离体大鼠心脏缺血/再灌注心功能及心肌凋亡的影响

目的:观察去势对离体大鼠心脏缺血／再灌注心脏功能和心肌凋亡的影响。方法:SD大鼠28只,随机分为去势组、对照组,每组14只。制备大鼠离体缺血／再灌注模型(缺血30min,再灌注2h),观察左室压力,再灌注结束后检测心肌梗死率和细胞凋亡指数,免疫组化技术检测心肌组织的Bcl-2、Bax水平。结果:(1)与对照组相比,去势组再灌注后的心脏左室收缩及舒张功能无显著变化(P>0．05);(2)去势组心肌梗死范围(43．68±6．89％)较对照组(39．33±7．85％)增加,但无统计学差异;(3)对照组和去势组间心肌细胞凋亡指数无统计学差异(P>0．05),心肌组织中Bcl-2、Bax含量未见显著变化。结论:去势对心脏缺血／再灌注心脏功能没有保护作用,而且不影响心肌细胞凋亡过程,生理剂量的雄激素对缺血再灌注后的心脏功能不产生损害作用。     

不同移植部位对成年大鼠睾丸间质细胞雄激素分泌功能的影响

目的:探索不同移植部位对移植的成年SD大鼠睾丸中睾丸间质细胞存活及雄激素分泌功能的影响。方法:将健康成年雄性SD大鼠随机分为对照组、假手术组、皮下组和肾包膜组。对照组大鼠不去势,其余大鼠于睾丸移植前1周行去势手术。对照组和假手术组去势后仅行背部皮肤切开,不进行睾丸移植;皮下组背部两侧各移植1/3个成年SD大鼠睾丸组织;肾包膜组每侧肾包膜下移植1/3个成年SD大鼠睾丸组织。4周后取材行HE和免疫组化染色,分析移植睾丸组织中睾丸间质细胞存活情况,ELISA法检测受体大鼠血清睾酮水平。结果:皮下组和肾包膜组移植物中难于见到完整的睾丸间质组织,但免疫组化染色发现大量HSD-17β1阳性细胞,对照组、皮下组和肾包膜组的HSD-17β1阳性细胞数分别为(24.33±4.30)、(9.83±4.05)和(12.67±2.81)个,对照组与皮下组相比差异具有统计学意义(p0.05);ELISA分析发现对照组、假手术组、皮下组和肾包膜组的血清睾酮浓度分别为(3.81±1.32)、(0.28±0.08)、(0.44±0.13)和(0.90±0.31)ng/m L,肾包膜组血清睾酮浓度高于假手术组(p0.01)和皮下组(p0.05),而皮下组血清睾酮水平高于假手术组,但两者差异无统计学意义(p0.05)。结论:移植的成年大鼠睾丸组织中的睾丸间质细胞可在受体肾包膜下或皮下存活,但肾包膜下移植可能更加有利于睾丸间质细胞存活和雄激素分泌。     

载脂蛋白E基因多态性与持续性植物状态的关系及其意义

研究载脂蛋白E(ApoE)基因多态性与持续性植物状态 (PVS)之间的关系 ,探讨PVS发生的遗传背景及其对血脂水平的影响。以 6 2名PVS患者为研究对象 ,5 5名正常人为对照 ,采用聚合酶链反应和限制性片段长度多态性(PCR RFLP)方法 ,分析了载脂蛋白E基因多态性 :血脂水平按常规酶法进行测定并进行统计学处理。ApoE基因多态分析表明 ,在PVS患者和正常人中观察到 5种ApoE基因型 ,分别为E3/ 3、E3/ 4、E2 / 2、E2 / 3及E4 / 2。PVS患者组ApoE3/ 4基因型频率高于对照组 (χ2 =14 .2 36 ,P <0 .0 0 1) ;而E3/ 3基因型频率较对照组显著降低 (χ2 =5 .348,P <0 .0 5 )。PVS患者的ε4等位基因频率显著高于对照组 (χ2 =10 .5 33,P <0 .0 0 1) ;而ε3等位基因频率显著低于对照组 (χ2 =7.0 2 2 ,P <0 .0 1)。两组ApoE基因型E2 / 2 ,E2 / 4 ,E2 / 3,E3/ 4的低密度脂蛋白胆固醇 (LDL C)水平之间存在统计学差异 (P <0 .0 5 ,P <0 .0 5 ,P <0 .0 5 ,P <0 .0 1)。ApoE基因多态性与PVS有关联 ,并影响患者的血脂水平。ApoE基因多态性可能与PVS的发生和预后有关     

睾酮对人血管内皮细胞产生NO、tPA和PAI-1的影响

目的:观察不同浓度睾酮对人血管内皮细胞生长、产生舒张因子及纤溶活性的影响.方法:体外培养人脐静脉内皮细胞(HUVEC),分为五个浓度睾酮组及单纯培养基对照组.做MTT实验观察睾酮对HUVEC生长的影响;还原酶法测定各组HUVEC释放NO量;ELISA法测定各组培养基中纤溶酶原激活物(tPA)及其抑制物(PAI-1)含量.结果:3×10-10mol/L-3×10-8mol/L睾酮组与对照组相比细胞生长良好,无明显差别;而大于生理剂量的两组(3×10-6～3×10-1mol/L)3 d后细胞生长明显受到抑制(P＜0.05).各浓度睾酮组产生NO量与对照组无明显区别.而3×10-10 mol/L～3×10-8 mol/L睾酮组tPA含量明显高于对照组(P＜0.01);大剂量组tPA产生明显减少(P＜0.01).所有实验组的PAI-1含量均明显降低.结论:生理及略低于生理剂量的睾酮对HUVEC生长及释放NO无不利影响,且增加纤溶活性.说明生理剂量睾酮对血管内皮功能、心血管系统有一定的保护作用,有利于防止动脉粥样硬化的发生、发展.     

蛇毒神经生长因子对大鼠坐骨神经损伤功能修复的时效作用研究

为研究蛇毒神经生长因子 ( SNGF)对大鼠坐骨神经损伤的修复的时效作用 ,作者应用 Wistar大鼠 5 0只建立大鼠坐骨神经钳夹损伤模型 ,随机分为单纯损伤组、生理盐水对照组、SNGF治疗用药 1 4、 2 1、 2 8天组 ,每组 1 0只。 SNGF治疗各组按实验模型制备处理后 ,即刻在损伤神经周围肌肉注射 SNGF ( 90 0 Bu/kg) ,以后每天肌注 1次 ,连续给药 1 4、 2 1和 2 8天 ,而生理盐水对照组每天肌注等量生理盐水。结果通过展爪反射观察到 ,1 4天组术后 1 1天开始恢复 ,平均恢复时间 1 6天 ;2 1天组术后 1 1天开始恢复 ,平均恢复时间 1 5天 ;2 8天…     

苦瓜皂甙降血糖作用及其机制初探

将雄性Wistar鼠 (体重 1 80± 1 0g)随机分为正常对照组 (NC)、实验对照组 (EC)和两个实验组 (E1、E2 ) ,其中NC、EC组饮用普通水 ,E1、E2组饮用水中分别含有苦瓜皂甙 1 0 0mg·L 1和 2 0 0mg·L 1。饲养五周后 ,后三组动物禁食 2 4h后取血待测 ;取血完毕即开始进食 ,2 4h后再次取血待测。一周后杀死动物取肌肉、肝脏标本检测糖原水平。结果显示苦瓜皂甙虽不影响禁食大鼠血浆胰岛素含量 ,却可明显升高血糖和皮质醇水平 ;显著降低进食后大鼠血糖和胆固醇水平 ,并维持适度的皮质醇水平。肌糖原和肝糖原含量明显增加     

Behavior of free testosterone in patients with prostate cancer on androgen deprivation therapy

OBJECTIVES: Determination of free testosterone (FT) serum level is an efficient method to evaluate bioavailable testosterone. We analyzed the behavior of serum FT in patients with prostate cancer receiving androgen deprivation therapy (ADT) and correlated FT with total testosterone (TT). We also analyzed the efficiency of both isoforms in the evaluation of the ADT. METHODS: Serum levels of TT and FT were determined in 191 patients with prostate cancer in a cross-sectional study. A subset of 56 patients submitted only to radical prostatectomy served as control group. The remaining 135 patients with advanced prostate cancer on three-month LHRH agonist treatment comprised the study group. The median age of the population was 73 years (range, 53-86 years) and the median time on ADT was 42 months (6-198). RESULTS: A significant correlation and linear regression between TT and FT was observed (r2 0.948). The efficiency of TT and FT to discriminate patients with and without ADT was similar (AUC: 0.993 and 0.995, respectively, p > 0.05). A castration level of serum FT established at 1.7 pg/mL had a sensitivity of 85.9% and a specificity of 100%, which are similar to the sensitivity and specificity of 50 ng/dL of TT. All patients without ADT had levels of serum TT and FT above the castration level. In 19 of the 135 (14.1%) patients on ADT serum TT was above 50 ng/dL. In 12 of these 19 patients (63.2%) serum FT was below 1.7 pg/mL while in seven patients (5.2%) FT was also above the castration level. CONCLUSIONS: The castration level of FT was established at 1.7 pg/mL. Serum TT and TF correlated very well; however, they seemed to provide complementary information in the evaluation of ADT efficiency. 14.1% of the patients on ADT failed to reach the castration level of serum TT; determination of serum FT in these patients would reduce this rate to 5.2%.     

Cortisol, adrenocorticotropic hormone and apolipoprotein synthesis in rat hepatocytes]

The influence of cortisol (5 mg/kg body wt administered daily for 5 and 10 days) on biosynthesis of apoproteins of lipoproteins of very low density in the liver and on the synthesis of apolipoproteins of very low, low, and high density (VLDL, LDL, and HDL apoproteins, respectively) in the blood serum of adrenalectomized animals, and after replacement cortisol therapy was studied. Cortisol treatment during these periods resulted in the VLDL apoproteins biosynthesis inhibition in the rat liver. The synthesis of apolipoproteins was increased by adrenalectomy; this effect was eliminated after replacement cortisol treatment. The apoprotein synthesis was stimulated within 5 hours by single injection of cortisol or ACTH. Study of the blood serum apolipoproteins specific radioactivity indicated metabolic change of lipoproteins, such as disturbed conversion from VLDL to LDL. Single and prolonged cortisol administration led to the opposite results. The authors believe that the metabolic disturbances of lipoproteins in the blood play a more important role in the pathogenesis of cortisol-induced hyperlipidemia than lipoprotein syntesis stimulation in the liver.     

Folic acid supplementation delays atherosclerotic lesion development in apoE-deficient mice

Folic acid is a vitamin that when used as a dietary supplementation can improve endothelial function. To assess the effect of folic acid on the development of atherosclerosis, male apolipoprotein E-deficient mice fed a standard chow diet received either water (control group) or an aqueous solution of folic acid that provided a dose of 75 microg/kg/day, for ten weeks. At the time of sacrifice, blood was drawn and the heart removed. The study measured plasma homocysteine, lipids, lipoproteins, low-density lipoprotein (LDL) oxidation, isoprostane, paraoxonase, and apolipoproteins, and aortic atherosclerotic areas. In folic acid-treated animals, total cholesterol, mainly carried in very low-density and low-density lipoproteins, increased significantly, and homocysteine, HDL cholesterol, paraoxonase, and triglyceride levels did not change significantly. Plasma isoprostane and apolipoprotein (apo) B levels decreased. The resistance of LDL to oxidization and plasma apoA-I and apoA-IV levels increased with a concomitant decrease in the area of atherosclerotic lesions. The administration of folic acid decreased atherosclerotic lesions independently of plasma homocysteine and cholesterol levels, but was associated with plasma levels of apolipoproteins A-I, A-IV and B, and decreased oxidative stress.     

Glucocorticoid-induced elevation of serum high-density lipoprotein-cholesterol and its reversal by adrenocorticotropin in the rat

The effect of administration of a high dose of glucocorticoid (triamcinolone) on serum lipids and lipoproteins was studied in rats. Changes in serum lipids, especially cholesterol, were most marked when 5 mg/kg body weight of triamcinolone was injected daily for 5 days. Serum lipoproteins were separated by ultracentrifugation followed by gel-filtration chromatography. Cholesterol distribution between apolipoprotein B-containing lipoproteins (very-low-density and low-density lipoproteins), high-density lipoprotein1 (HDL1), and HDL2 was determined after administration of triamcinolone with or without additional treatment with adrenocorticotropin (ACTH; Cortrosyn, 6 IU/rat). When triamcinolone was administered, cholesterol concentrations in HDL1 and HDL2 were elevated in a dose-dependent manner, but there was no significant change in apolipoprotein B-containing lipoprotein cholesterol levels. When ACTH was administered in combination with triamcinolone, the concentrations of all serum lipids except triacylglycerol were significantly lowered compared with rats treated with triamcinolone alone. HDL1-cholesterol concentration in serum was significantly (P less than 0.001) lowered from 69 +/- 13 mg/dl (mean +/- S.D.) in triamcinolone-treated rats to 36 +/- 4 mg/dl by the administration of ACTH plus triamcinolone. The additional administration of ACTH in triamcinolone-treated rats caused a slight, but significant, decrease in cholesterol concentration in apolipoprotein B-containing lipoproteins; however, HDL2-cholesterol level was not significantly affected, although there was a tendency for it to be lowered.     

Uptake and degradation of human very-low-density lipoproteins by rat liver endothelial cells in culture

Rat liver endothelial cells in primary cultures take up and degrade 125I-labelled human very-low-density lipoproteins (VLDL) in a saturable fashion at physiological triacylglycerol concentrations. The iodinated VLDL are readily taken up by the freshly isolated endothelial cells and degradation products appear in the medium about 30 min after the addition of VLDL to the cultures. Uptake and degradation at 37 degrees C are effectively inhibited by unlabelled human VLDL, low-density lipoproteins (LDL), high-density lipoproteins and lymph chylomicrons, but only modestly by acetylated LDL. Purified apolipoproteins E and C-III:1 also compete with the uptake of iodinated VLDL, but when degradation was studied for longer periods of time, such a competition could not be demonstrated. This may be due to the fact that the added apolipoproteins become associated with the lipoproteins. In binding experiments at 7 degrees C, iodinated apolipoprotein C III:1 bound to the liver endothelial cells in a manner characteristic of receptor binding with a dissociation constant of 0.5 microM. This binding could not only be inhibited by unlabelled apolipoprotein C-III:1 but also by unlabelled apolipoprotein E. The results indicate that rat liver endothelial cells carry receptors for VLDL and that these recognize the apolipoproteins E, C-III and B on the lipoprotein surface. Considering the large endothelial surface and high blood flow through the liver, significant quantities of lipoproteins can be taken up and degraded, thus influencing the levels of circulating lipoproteins in the in vivo situation.     

Modified apolipoprotein pattern after irradiation of human high-density lipoproteins by ultraviolet B.

The ultraviolet B-induced destruction of tryptophan residues and lipid peroxidation of high-density lipoproteins is accompanied by the immediate and marked structural modification of the apolipoproteins, as revealed by SDS-polyacrylamide gel electrophoresis and immunoblot with specific monoclonal antibodies. Formation of several polymers of apolipoprotein A-I, apolipoprotein A-II or both apolipoproteins occurred, although apolipoprotein A-II did not contain any Trp residue. These results suggest that initial photochemical damage can be transferred via intramacromolecular processes to other sites within the same apolipoprotein and by intermacromolecular reactions from apolipoprotein A-I to other apolipoproteins. In both cases, lipid peroxidation enhances the propagation of the initial photochemical damage. The physiological significance of this work is discussed with respect to the low-light doses required for the alterations of the high-density lipoproteins.     

慢性应激状态下大鼠睾酮水平测定

目的通过对于慢性应激模型和运动疲劳模型大鼠的血清睾酮水平的对比研究,探讨慢性应激过程中睾酮水平变化规律及其与发生疲劳的关系。方法建立大鼠慢性不可预测性应激模型及运动性疲劳模型;应用大鼠轨迹追踪系统对不同应激时间大鼠进行活动量观测,应用放射性免疫法对各组大鼠进行血清总睾酮和游离睾酮进行测定。结果与正常组比较,慢性应激大鼠第1周组活动量(运动轨迹长度,下同)增加(P0.01),第2周组活动量下降(P0.01)。各实验组大鼠游离睾酮与总睾酮之间均存在线性相关。慢性应激各组随应激时间延长,其游离睾酮与总睾酮比值呈逐渐下降趋势,并且能够达到运动疲劳组水平。结论慢性应激条件可以明显引起大鼠睾酮水平下降。提示分层检测慢性疲劳综合征人群血清总睾酮及游离睾酮的水平以及进行动态性研究可能为本病症的诊断提供生化指标。以游离睾酮与总睾酮比值为指标检测雄性激素水平,能够更好地反映干预因素对动物生理上的影响。     

Luteinizing hormone release by gonadotropin releasing hormone before and after castration in bulls

The magnitude of gonadotropin releasing hormone (GnRH) induced lutei nizing hormone (LH) release prior to castration, following castration, a nd during testosterone replacement in males, was compared, using 6 9-mon th-old Holstein bulls. Also, the effects of castration and testosterone replacement on patterns of episodic changes in serum LH were studied. Blood samples were collected at hourly intervals for 24 hours prior to castration, at 21 days after castration, and at 23 days postcastration a fter testosterone, 20 mg thrice daily, has been given for 24 hours. Each animal was given GnRH, 40 mcg iv, at 24 hours before castration, at 7 and 14 days after castration, and at 28 days postcastration following 6 days of testosterone treatment. GnRH caused LH release before and after castration. The LH increase was 2.5-fold at 14 days postcastratio n. Testosterone replacement did not reduce the magnitude of LH response to GnRH to precastration levels. The number of episodic increases in serum LH prior to castration averaged 3.7 daily and increased to 6.5 daily at 21 days after castration (p less than .05). The magnitude of increase in LH concentration in these epidsodic events was not affected by castration. Testosterone replacement failed to restore either the average number or change the magniture of LH increase above precastratio n levels. It was shown that LH is normally released episodically in bulls. The peaks of LH release were followed by increased testosterone in serum. Results suggest that LH release in bulls is controlled by gonadic factors other than testosterone.