睾丸外组织雄激素受体的分布及检测

雄激素受体 (AR)是介导雄激素在靶细胞中发挥作用的关键大分子 ,主要存在于男性睾丸组织中。本文综述了AR及其mRNA在泌尿生殖系统的前列腺、附睾、阴茎皮肤等睾丸外组织 ,头皮、海马旁回、脂肪等非泌尿生殖系统组织及在胃癌、喉癌等睾丸外肿瘤组织中的分布情况 ,并对AR的检测方法进行了复习 ,以进一步研究循环血中雄激素对人体各系统的作用     

Daxx基因在小鼠睾丸精子发生过程中的表达特征

目的:研究死亡结构域相关蛋白(Daxx)基因在小鼠睾丸精子发生过程中的表达特征,初步探讨其在生精过程中的作用。方法:通过实时荧光定量PCR(q PCR)、Western印迹及免疫荧光等方法检测Daxx在不同周龄野生型小鼠睾丸组织以及成年睾丸支持细胞雄激素受体特异性敲除(SCARKO)和雄激素受体敲除(ARKO)小鼠睾丸中的表达特征。结果:q PCR、Western印迹和免疫荧光结果表明,Daxx基因在出生4周后小鼠睾丸中高表达,且主要定位于细胞核;与野生型小鼠相比,SCARKO小鼠睾丸中DAXX的表达差异不显著(0.853±0.058 vs1.000±0.015),但在生精细胞细胞核中呈极性分布;DAXX在ARKO小鼠睾丸表达显著降低(0.299±0.026 vs1.000±0.015,P0.01)。结论 :Daxx基因在小鼠睾丸发育中期时表达最高。ARKO小鼠中DAXX的表达与野生型相比显著降低,睾丸支持细胞中AR基因特异性敲除影响DAXX定位。DAXX可能参与调控小鼠的精子发生过程。     

成年糖尿病大鼠睾丸、附睾和前列腺内雄激素受体的表达研究

目的:观察糖尿病大鼠睾丸、附睾和前列腺内是否存在雄激素受体(AR)的异常表达。方法:用链脲菌素(STZ)诱导成年大鼠糖尿病模型,实验分正常对照组(C组)、糖尿病组(D组)及胰岛素治疗组(ID组),分别以Northern印迹及放射配基法检测睾丸、附睾和前列腺内AR的mRNA及蛋白质水平。结果:D和ID组血清睾酮水平低于C组(P<0.05);附睾内D和ID组AR的mRNA水平低于C组(P<0.05),睾丸和前列腺内D组AR的蛋白质水平低于C组(P<0.05)。结论:糖尿病大鼠睾丸、附睾和前列腺内AR的表达降低,从而削弱了雄激素的生物利用度,这可能是导致患病大鼠性与生殖功能障碍的原因之一。     

【特刊综述】利用雄激素受体敲除（ARKO）小鼠模型认识人类雄激素缺乏

雄激素的作用机理很复杂。最近,使用转基因修饰小鼠模型进行的雄激素受体研究使我们对雄激素作用机理有了更进一步的理解。Cre-loxP系统能够完成组织和／或细胞特异性的敲除。通过使用Cre—loxP系统已经获得了大量整体性或组织特异性雄激素受体（ARK0）敲除模型。这些ARKO模型的多个雄激素作用位点,包括心血管系统、免疫和造血系统、骨骼、肌肉、脂肪组织、前列腺和脑,均已被检测。本篇综述着重阐述了通过针对这些雄激素作用位点的ARKO小鼠模型而取得的人类雄激素缺乏的研究成果,并且指出充分理解Cre-loxPdx鼠模型的优缺点才能正确认识其表型。     

去泛素化酶24基因在小鼠睾丸精子发生过程中的表达特征

目的:研究去泛素化酶24(USP24)基因在小鼠睾丸精子发生过程中的表达特征,初步探讨其在生精过程中的作用。方法:通过实时荧光定量PCR(qPCR)和免疫荧光等方法检测USP24在不同周龄野生型小鼠睾丸组织以及成年雄激素受体敲除(ARKO)小鼠睾丸中的表达特征;采用双荧光素酶报告基因实验检测USP24启动子转录活性。结果:qPCR和免疫荧光结果表明,USP24基因在出生1周时表达水平较低,3周时急剧升高,随后维持在相似水平至第8周;USP24主要定位于支持细胞和生精细胞的细胞质;与野生型相比,USP24在ARKO小鼠睾丸表达降低;性成熟小鼠睾丸中,USP24定位于成熟精子头部后端及中部。双荧光素酶报告基因实验结果显示,睾酮刺激后USP24启动子的转录活性升高。结论:USP24基因的表达水平的升高与小鼠的性发育相关,且其蛋白在小鼠成熟精子上表达。USP24是受雄激素受体(AR)调控的靶基因。USP24可能参与调控小鼠的精子发生过程。     

中药消癃通闭对犬前列腺组织中T、E_2、DHT、AR和5α-还原酶的影响

取前列腺增生老龄犬,经口喂给消癃通闭药粉32天后,用RIA技术测定前列腺组织中睾酮(T)、雌二醇(E_2)、双氢睾酮(DHT),并与血清中浓度对照;用Scatchard Plots方法及双复管单点法测定雄激素受体(AR);用酶学法测定5α—还原酶Ⅰ、Ⅱ型。结果发现:正常犬微粒体中5α—还原酶Ⅰ型的活性为97.145±45.729,Ⅱ型的活性为15.745±15.093(单位均为DHT Pmol/mg Pro—tein·30min~(-1),下同)。予消癃通闭lg/kg·d~(-1)组犬的测定值分别为92.454±57.703和11.328±10.060;给予消癃通闭2g/kg·d~(-1)组犬的测定值分别为42.837±31.909和9.288±11.209。各组的前列腺组织中AR的测定值无明显差异。提示消癃通闭治疗前列腺增生的机理为抑制前列腺组织中5α—还原酶的活性。     

睾酮对体外大鼠阴茎海绵体组织细胞增殖的影响

目的:探讨睾酮对雄性SD大鼠阴茎海绵体组织细胞增殖的影响。方法:无菌条件下获取大鼠阴茎海绵体组织,免疫组化法检测其雄激素受体的表达,再分别采用酶消化法培养平滑肌细胞和贴壁法培养成纤维细胞,用四氮唑蓝(MTT)还原法观察对照组及睾酮10-8mol/L、10-7mol/L、10-6mol/L、10-5mol/L、10-4mol/L、10-3mol/L浓度组对海绵体组织细胞增殖的影响。结果:雄激素受体在大鼠阴茎海绵体组织表达,10-5mol/L睾酮刺激可促进大鼠阴茎海绵体平滑肌细胞和成纤维细胞增殖,MTT还原法测定分别为68100±2200和70200±1300(P<0.05);10-4mol/L睾酮刺激可抑制平滑肌细胞和成纤维细胞增殖,MTT法测定A值为分别55000±1400和59100±1500(P<0.01);其他组作用不显著。结论:大鼠阴茎海绵体组织存在雄激素受体,睾酮可经雄激素受体途径对阴茎海绵体组织细胞增殖的产生影响,不同浓度睾酮可促进或抑制海绵体平滑肌细胞和成纤维细胞的增殖。     

雌激素受体在雄性生殖系统中的分布及其对雄性生殖的作用

与雄激素一样,雌激素对雄性生殖也起重要调控作用。雌激素与雌激素受体(ER)结合后,产生基因组效应或非基因组效应。ER包括ERα和ERβ。在雄性生殖系统包括睾丸、附睾、前列腺及阴茎中均有ER分布。ERα基因敲除小鼠精子发生过程明显受损,而ERβ基因敲除后小鼠精子发生仍可维持正常,提示两种ER亚型对精子发生的作用不同。ERα和ERβ还可能存在相互补偿作用。     

雄激素/雄激素受体对小鼠附睾Caveolin-1表达调控机制的研究

目的:探讨雄激素和雄激素受体(AR)对小鼠附睾Caveolin-1表达的调控机制。方法:通过搜索前期染色体免疫共沉淀-测序(ChIP-seq)实验得到的小鼠附睾AR结合位点的数据库,寻找Caveolin-1基因相关联的AR结合位点。分别取正常小鼠、睾丸阉割小鼠以及睾丸阉割后补充外源雄激素的小鼠的附睾组织,一方面,抽提总RNA,利用逆转录PCR以及逆转录荧光定量PCR检测Caveolin-1基因的mRNA表达水平;另一方面,利用AR抗体进行染色体免疫共沉淀(ChIP),采用ChIP-PCR以及ChIP-qPCR的方法,检测Caveolin-1基因相关联的AR结合位点在体内与AR的结合情况。结果:从小鼠附睾AR结合位点的数据库中找到两个Caveolin-1相关联的AR结合位点,均位于第二内含子区域。睾丸阉割后,Caveolin-1基因的表达显著升高(P<0.05),表达量是对照组的(1.8±0.17)倍;两个AR结合位点的富集倍数分别由正常状态下的(13.5±1.47)倍和(10.5±1.03)倍降至(1.05±0.17)倍和(1.4±0.14)倍(P<0.01)。补充雄激素后,Caveolin-1基因的表达又降至正常水平(P<0.05),为正常对照组的(1.03±0.06)倍。两个AR结合位点的富集倍数则分别升至(16.4±2.6)倍和(10.0±0.92)倍(P<0.01)。结论:Caveolin-1在小鼠附睾内是AR的一个直接靶基因,其表达受雄激素的负调控。该研究为理解雄激素/AR在小鼠附睾内的调控网络提供了新的视角。     

中年男性雄激素部分缺乏症的睾酮补充治疗

目的　观察睾酮补充治疗对中年男子雄激素部分缺乏症的疗效。　方法　2001年12月至2004年4月男科门诊经雄激素部分缺乏问卷评分、血清总睾酮(TT)和游离睾酮(fT)测定筛选出雄激素部分缺乏症患者179例,平均年龄41. 8岁,无器质性疾病和病原体感染。136例作为治疗组予口服十一酸睾酮3个月, 80mg/次,每日早餐、晚餐时各1次, 43例作为对照组未予特殊治疗。观察比较治疗前后雄激素部分缺乏评分和性激素的变化。　结果　治疗组治疗后1、3个月雄激素部分缺乏评分总分和构成评分与治疗前比较明显改善(P均<0. 01 )。治疗前患者TT、fT、雌二醇分别为(11. 9±0. 9)nmol/L、(40. 6±11. 8)pmol/L、( 128. 1±40. 1 )pmol/L。治疗后3个月分别为( 19. 1±1. 2)nmol/L, (75. 2±17. 0)pmol/L, (100. 6±27. 5)pmol/L,差异均有统计学意义(P均<0. 01 )。对照组雄激素部分缺乏评分总分和构成评分及性激素水平无显著变化。　结论　中年男子雄激素部分缺乏症在临床上客观存在,睾酮补充治疗对中年雄激素部分缺乏症安全、有效。     

Vasopressor hormone response following mesenteric traction during major abdominal surgery

Background : We investigated the vasopressor hormone response following mesenteric traction (MT) with hypotension due to prostacyclin (PGI₂) release in patients undergoing abdominal surgery with a combined general and epidural anesthesia. Methods : In a prospective, randomized, placebo-controlled study we administered 400 mg ibuprofen (i.v.) in 42 patients scheduled for abdominal surgery. General anesthesia was combined with epidural anesthesia (T4-L1). Before as well as 5, 15, 30, 45, and 90 min after MT we recorded plasma osmolality, hemodynamics and measured 6-keto-PGFlα (stabile metabolite of PGI₂), TXB₂ (stabile metabolite of thromboxane A₂) active renin, and arginine vasopressin (AVP) plasma concentrations by radioimmunoassay. Catecholamine levels were assessed by high-pressure liquid chromatography (HPLC) with electrochemical detection. Results : Following MT, arterial hypotension occurred along with a substantial PGI₂ release. This was completely abolished by ibuprofen administration. Although plasma levels of 6-keto-PGF_1α (1133 (708) vs. 60 (3) ng/L, median (median absolute deviation), P=0.0001, placebo vs. ibuprofen) remained significantly elevated, blood pressure was restored within 30 min after MT in the placebo group. At the same point in time plasma concentrations of TXB² (164 (87) vs. 58 (1) ng/L, P=0.0001), epinephrine (46 (33) vs. 14 (6) ng/L, P=0.001), AVP (41 ± (18) vs. 12 (7) ng/L, P=0.0004), and active renin (27 (12) vs. 12 (4) ng/L, P = 0.001) were significantly higher in placebo-treated patients. Conclusion : Under combined general and epidural anesthesia arterial hypotension following MT due to endogenous PGI₂ release is associated with enhanced release of AVP, active renin, epinephrine and thromboxane A₂, presumably contributing to hemodynamic stability within 30 min after MT.     

A Teaspoon Pump for Pumping Blood with High Hydraulic Efficiency and Low Hemolysis Potential

Abstract: Virtually all blood pumps contain some kind of rubbing, sliding, closely moving machinery surfaces that are exposed to the blood being pumped. These valves, internal bearings, magnetic bearing position sensors, and shaft seals cause most of the problems with blood pumps. The original teaspoon pump design prevented the rubbing, sliding machinery surfaces from contacting the blood. However, the hydraulic efficiency was low because the blood was able to "slip around" the rotating impeller so that the blood itself never rotated fast enough to develop adequate pressure. An improved teaspoon blood pump has been designed and tested and has shown acceptable hydraulic performance and low hemolysis potential. The new pump uses a nonrotating "swinging" hose as the pump impeller. The fluid enters the pump through the center of the swinging hose; therefore, there can be no fluid slip between the revolving blood and the revolving impeller. The new pump uses an impeller that is comparable to a flexible garden hose. If the free end of the hose were swung around in a circle like half of a jump rope, the fluid inside the hose would rotate and develop pressure even though the hose impeller itself did not "rotate"; therefore, no rotating shaft seal or internal bearings are required.     

A comparison of the inhibitory effects of four volatile anaesthetics on the metabolism of chlorzoxazone, a substrate for CYP2E1, in rabbits

Background: Halothane inhibits in vitro and in vivo activity of cytochrome P-450 (CYP) 2E1. There are several fluorinated volatile anaesthetics besides halothane, and most of them are defluorinated by CYP2E1. It is unclear whether other fluorinated anaesthetics inhibit the in vivo activity of CYP2E1.
Methods: We compared the inhibitory effects of therapeutic concentrations of four inhalational anaesthetics, halothane, enflurane, isoflurane, and sevoflurane, on chlorzoxazone metabolism in rabbits receiving artificial ventilation.
Results: All four inhalational anaesthetics decreased arterial blood pressure and increased plasma chlorzoxazone concentration. However, no significant differences in the plasma chlorzoxazone concentration were found between the four anaesthetics. The estimated chlorzoxazone clearance increased after beginning inhalation with all four agents, but no significant difference in clearance was noted between agents.
Conclusions: At therapeutic concentrations, the in vivo inhibitory effect on chlorzoxazone metabolism was similar for all four inhalational anaesthetics examined, even though their chemical characteristics and extent of hepatic metabolism differ considerably.     

Microspheres Based Detoxification System: A New Method in Convective Blood Purification

Abstract: A variety of protein-bound or hydrophobic substances, accumulating as a result of pathologic conditions such as exogenous or endogenous intoxications, are removed poorly by conventional detoxification methods because of low accessibility (hemodialysis), insufficient adsorption capabilities (hemosorption), low efficiency (peritoneal dialysis), or economic limitations (high-volume plasmapheresis). Combining advantages of existing methods with microspheric technology, a module-based system was designed. Major operating parameters of the latter can be modified to allow for adjustment to individual clinical situations. An extracorporeal blood circuit including a plasmafilter is combined with a secondary high-velocity plasma circuit driven by a centrifugal pump. Different microspheric adsorbers can be combined in one circuit or applied in sequence. Thus, a prolonged treatment can be tailored using specially designed selective adsorber materials. Comparing this system with existing methods (high-flux hemodialysis, molecular adsorbent recycling system), results from our in vitro studies and animal experiments demonstrate the superior efficiency of substance removal.     

Tissue perfusion in relation to cardiac output during continuous positive-pressure ventilation and administration of propranolol or verapamil

Background : Our objective was to determine whether administration of propranolol or verapamil modifies the hemodynamic adaptation to continuous positive-pressure ventilation (CPPV), in particular the regional distribution of cardiac output (CO).
Methods : General hemodynamics and regional blood flows assessed by microsphere technique (15 (μm) were recorded in 16 anesthetized pigs during spontaneous breathing (SB) and CPPV with 8 cm H₂O end-expiratory pressure (CPPV8) before and after intravenous administration of propranolol (0.3 mg · kg⁻¹ followed by 0.15 mg · kg⁻¹ · h⁻¹, n=8) or verapamil (0.1 mg · kg⁻¹ followed by 0.3 mg · kg⁻¹ · h⁻¹, n=8).
Results : CPPV8 depressed CO by 25% without shifts in its relative distribution with the exception of a noteworthy increase in adrenal perfusion. Propranolol increased arterial blood pressure, and due to a fall in heart rate, CO dropped by 25%. The kidneys and, to a lesser extent, the splanchic region and central nervous system received increased fractions of the remaining CO at the expense of skeletal muscle flow. Similar patterns were seen during SB and CPPV8 such that the combination of propranolol and CPPV8 depressed CO by 50%. The circulatory effects of verapamil were less evident but myocardial perfusion tended to increase.
Conclusions : The combination of propranolol or verapamil with CPPV does not result in any specific hemodynamic interaction in anesthetized pigs, except that the combined effect of propranolol and CPPV may severely reduce CO.     

Bariatric Surgery in Some "Central and East-European (former Eastern bloc)"Countries - Current Status and Prediction for the Next Millennium

Background: Obesity is increasing globallly, including in the formerly "Eastern Bloc" countries. Methods: A survey was made of obesity and bariatric surgery. Results: In the 8 East and Central European countries studied, with total population 300 million, roughly 43% of the population was overweight (BMI 25-30), 23% obese (BMI > 30), with about 15 million people morbidly obese (BMI > 40). From 0-10 morbidly obese individuals/100,000/year undergo bariatric surgery. Conclusion: Most countries were found to provide inadequate treatment for obesity.The majority of the morbidly obese are not treated effectively. However, health-care awareness of obesity and bariatric surgeons are slowly increasing.     

Volatile anaesthetics reduce adhesion of blood platelets under low-flow conditions in the coronary system of isolated guinea pig hearts

Background : Inhibitory effects of volatile anaesthetics on platelet aggregation have been demonstrated in several studies. However, the influence of volatile anaesthetics on intracoronary platelet adhesion has not been elucidated so far.
Methods : Isolated hearts of guinea pigs were perfused with buffer in the absence or presence of volatile anaesthetics (0.5 and 1 MAC) at constant coronary flow rates of 5 ml/min for 25 min, then 1 ml/min for 30 min and again 5 ml/min for 10 min. Before, during and after low-flow perfusion, a bolus of human platelets was applied into the coronary system. To simulate thrombogenic conditions, 0.3 U/ml human thrombin was infused during low-flow perfusion and reperfusion. The number of platelets sequestered to the endothelium was calculated from the difference between coronary in- and output of platelets. The myocardial production of lactate and consumption of pyruvate and coronary perfusion pressure were also determined.
Results : At a flow rate of 5 ml/min only about 3% of the applied platelets did not emerge from the coronary system, in any group. In contrast, 13.1±1.2% (mean±SEM) of infused platelets became adherent in low-flow perfusion in the control group without anaesthetic. The adherence was reduced with each 1 MAC isoflurane (to 6.2±1.2%), sevoflurane (to 4.4±0.9%) or halothane (to 3.2±1.5%) (each P <0.05 vs. control). Volatile anaesthetic, 0.5 MAC, did not inhibit platelet adhesion to a statistically significant extent in any case. Perfusion pressure and metabolic parameters were not statistically different between the control and the hearts exposed to anaesthetics.
Conclusion : Volatile anaesthetics in a concentration of 1 MAC can reduce the adhesion of platelets in the coronary system under reduced flow conditions. This action does not arise from vasodilation or inhibition of ischaemic stress.     

Synergistic interaction between the effects of propofol and midazolam with fentanyl on phrenic nerve activity in rabbits

Background: It has been shown that the depressive effects of both propofol and midazolam on consciousness are synergistic with opioids, but the nature of their interactions on other physiological systems, e. g. respiration, has not been fully investigated. The present study examined the effect of propofol and midazolam alone and in combination with fentanyl on phrenic nerve activity (PNA) and whether such interactions are additive or synergistic. Methods: PNA was recorded in 27 anaesthetised and artificially ventilated rabbits. In three groups, propofol, fentanyl and midazolam were administered intravenously in incremental doses to construct dose-response curves for the depressant effects of each one on PNA. In another two groups, the effect of pretreatment with either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. on the effects of propofol and fentanyl respectively on PNA were studied. Results: Propofol and fentanyl caused a dose-dependent depression of PNA with complete abolition at the highest total doses of 16 mg · kg^?1 i. v. and 32 μg · kg^?1 i. v., respectively. In contrast, midazolam in incremental doses to a total of 0.8 mg · kg^?1 reduced mean PNA by 63%, but approximately 12% of PNA remained at a total dose as high as 6.4 mg · kg^?1. The mean ED₅₀s, calculated from dose-response curves, were 5.4 mg · kg^?1, 3.9 μg · kg^?1 and 0.4 mg · kg^?1 for propofol, fentanyl and midazolam, respectively. Initial doses of either fentanyl 1 μg · kg^?1 i. v. or midazolam 0.05 mg · kg^?1 i. v. acted synergistically with subsequent doses of either propofol or fentanyl to abolish PNA at total doses of 8 mg · kg^?1 and 8 μg · kg^?1, respectively. Conclusion: Fentanyl has a synergistic interaction with both propofol and midazolam on PNA and hence potentially on respiration.     

Influence of dopexamine hydrochloride on haemodynamics and regulators of circulation in patients undergoing major abdominal surgery

Background: Catecholaminergic support is often used to improve haemodynamics in patients undergoing major abdominal surgery. Dopexamine is a synthetic vasoactive catecholamine with beneficial microcirculatory properties. Methods: The influence of perioperative administration of dopexamine on cardiorespiratory data and important regulators of macro- and microcirculation were studied in 30 patients undergoing Whipple pancreaticduodenectomy. The patients received randomized and blinded either 2 μg · kg^?1 · min^?1 of dopexamine (n=15) or placebo (n=15, control group). The infusion was started after induction of anaesthesia and continued until the morning of the first postoperative day. Endothelin-1 (ET-1), vasopressin, atrial natriuretic peptide (ANP), and catecholamine plasma levels were measured from arterial blood samples. Measurements were carried out after induction of anaesthesia, 2 h after onset of surgery, at the end of surgery, 2 h after surgery, and on the morning of the first postoperative day. Results: Cardiac index (CI) increased significantly in the dopexamine group (from 2.61±0.41 to 4.57±0.78 1 · min^?1 · m^?2) and remained elevated until the morning of the first postoperative day. Oxygen delivery index (DO₂I) and oxygen consumption index (VO₂I) were also significantly increased in the dopexamine group (DO₂I: from 416±91 to 717±110 ml/m² · m²; VO₂I: from 98±25 to 157±22 ml/m² · m²), being significantly higher than in the control group. pHi remained stable only in the dopexamine patients, indicating adequate splanchnic perfusion. Vasopressive regulators of circulation increased significantly only in the untreated control patients (vasopressin: from 4.37±1.1 to 35.9±12.1 pg/ml; ET-1: from 2.88±0.91 to 6.91±1.20 pg/ml). Conclusion: Patients undergoing major abdominal surgery may profit from prophylactic perioperative administration of dopexamine hydrochloride in the form of improved haemodynamics and oxygenation as well as beneficial influence on important regulators of organ blood flow.     

Systemic analgesia adapted to the children's condition

A concept of balanced analgesia using nonsteroidal anti-inflammatory drugs (NSAIDs), paracetamol (acetaminophen), opioids, and corticosteroids can also be used in patients with pre-existing illnesses. NSAIDs are the most effective treatment for acute pain of moderate intensity in children; however, these drugs should be avoided in patients at increased risk for serious side effects, e.g. patients with renal impairment, bleeding tendency, or extreme prematurity. NSAIDs can be given with minimal risks to the younger child with mild to moderate asthma, and, in these patients, the use of steroids can be encouraged; in addition to their antiemetic and analgesic action, a beneficial effect on asthma symptoms can be expected. In the non-intubated child with cerebral trauma, exaggerated sedation caused by opioids and increased bleeding tendency caused by NSAIDs must be avoided. In neonates and small infants, the oral administration of sucrose or glucose is helpful to minimize pain reaction during short uncomfortable interventions.