Hhcy大鼠阴茎海绵体内NOS及CO含量的研究

目的:检测高同型半胱氨酸血症(Hhcy)大鼠阴茎组织内一氧化氮合酶(NOS)和一氧化碳(CO)的含量并探讨其对阴茎勃起功能的影响。方法:取成年雄性Wistar大鼠20只,随机均分为2组:正常对照组和Hhcy组。Hhcy组给予3%高蛋氨酸饲料喂养,正常对照组给予普通饲料喂养,4周后取血,测定血清Hhcy含量;取阴茎海绵体组织、匀浆,测定NOS和CO的含量。结果:Hhcy组血清中同型半胱氨含量[(22.32±1.65)μmol/L]显著高于正常对照组[(4.90±1.73)μmol/L],阴茎组织中的NOS[(6.45±1.12)nmol/(g·min)]和CO[(10.60±0.92)μmol/L]含量明显低于正常对照组[(10.77±0.60)nmol/(g·min)和(13.36±0.44)μmol/L]。结论:给予4周高蛋氨酸饮食的Wistar大鼠能引起Hhcy。Hhcy大鼠阴茎海绵体组织中内源性NOS和CO降低。Hhcy是大鼠阴茎勃起功能障碍的独立危险因素。     

尼古丁对大鼠阴茎海绵体内源性CO浓度及NOS活性的影响

目的:观察尼古丁对成年雄性大鼠阴茎海绵体内源性一氧化碳(CO)浓度及一氧化氮合酶(NOS)活性的影响,探讨吸烟对勃起功能损害的可能机制。方法:40只成年雄性Wistar大鼠分为4组,尼古丁注射1个月组、2个月组、3个月组和对照组,尼古丁注射组尼古丁0.5 mg/(kg.d)皮下分别注射1、2、3个月,对照组注射生理盐水。处理后,取阴茎海绵体,用改良双波长分光光度法检测CO浓度,改良Griess法检测NOS活性。结果:对照组CO浓度为(13.66±0.40)μmol/mg prot,NOS活性为(9.72±0.47)U/mg prot。尼古丁注射1个月,CO浓度和NOS活性分别下降为(12.43±0.56)μmol/mg prot和(8.44±0.69)U/mg prot,显著低于对照组(P均<0.01);尼古丁注射2个月,CO浓度和NOS活性分别下降为(11.41±0.52)μmol/mg prot和(7.53±0.24)U/mg prot,显著低于对照组和尼古丁注射1个月组(P<0.01);尼古丁注射3个月,海绵体CO浓度和NOS活性分别下降为(10.52±0.59)μmol/mg prot和(6.64±0.31)U/mg prot,均显著低于对照组和尼古丁注射1个月、2个月组(P均<0.01)。结论:尼古丁可导致成年雄性大鼠阴茎海绵体内源性CO浓度及NOS活性下降,提示内源性CO及NOS参与吸烟引起勃起功能障碍的病理生理过程。     

甲状腺素对大鼠阴茎海绵体内NOS及CO含量影响的研究

目的:建立甲状腺功能亢进及甲状腺功能减退Wistar大鼠动物模型,检测其阴茎海绵体内NOS及内源性一氧化碳(CO)的含量,探讨甲状腺素对大鼠勃起功能的影响及内源性CO在阴茎海绵体勃起过程中的作用,进一步讨论甲状腺素对人类勃起功能的影响。方法:将50只3月龄雄性Wistar大鼠随机均分为甲亢组、甲亢治疗组、甲减组、甲减治疗组及正常对照组。用紫外分光光度计分别测定阴茎海绵体内NOS及CO的含量。结果:无论甲状腺素增多及减少都会使大鼠阴茎海绵体NOS含量降低(P<0.01),并且甲减组阴茎海绵体内NOS活性低于甲亢组(P<0.01)。无论甲状腺素增多还是减少都会使大鼠阴茎海绵体内CO含量降低(P<0.01),并且甲亢组阴茎海绵体内CO活性低于甲减组(P<0.01)。在对甲减组及甲亢组进行治疗后其CO及NOS的含量得到提高,与正常对照组无显著差异(P>0.05)。结论:甲状腺功能紊乱情况下阴茎海绵体中NOS和CO的浓度均减低;甲状腺功能紊乱被及时纠正后阴茎海绵体中CO及NOS的含量可恢复到正常水平。在相同条件下甲状腺功能低下对性功能的损害强于甲状腺功能亢进对勃起功能的损害。     

衰老对大鼠阴茎海绵体NOS I的表达和NOS活性的影响

目的 :探讨衰老对大鼠阴茎海绵体一氧化氮合酶Ⅰ (NOSⅠ)mRNA、蛋白的表达和NOS活性的影响。　方法 :30只雄性SD大鼠按不同月龄分为成年组、老年组和衰老组 ,应用Western印迹、RT PCR方法分别检测不同年龄组阴茎海绵体NOSⅠ蛋白及mRNA的表达 ;用紫外分光光度计测定不同年龄组阴茎海绵体NOS的活性。　结果 :成年组NOSⅠ 蛋白的表达量最高 ,老年组和衰老组显著降低 ,分别为成年组的 75 .6 %和 6 1.2 % ;NOSⅠmRNA的表达与蛋白表达的变化一致 ;老年组NOS活性与成年组差异无显著性 (P >0 .0 5 ) ,衰老组NOS活性明显降低 ,是成年组的70 .4 % ,并且差异非常显著 (P <0 .0 1)。　结论 :衰老引起NOSⅠ 蛋白及mRNA的表达降低和NOS活性的显著降低 ,可能是老年性阴茎勃起功能障碍的主要机制之一。     

血红素氧合酶2在去势大鼠阴茎海绵体内的表达

目的:研究去势大鼠阴茎海绵体血红素氧合酶2(HO-2)和内皮型一氧化氮合酶(eNOS)的表达,探讨雄激素与HO-2、eNOS在ED中的作用及相关性。方法:10周龄雄性SD大鼠40只,分为4、8、12周组和正常对照组各10只,实验组采取手术切除双侧睾丸,对照组采取假手术。分别于术后4、8、12周测定大鼠血清睾酮(T)、阴茎海绵体内压(ICP)、平均颈动脉压(MAP),取阴茎标本,采用Western印迹分析阴茎海绵体HO-2含量,免疫组化分析HO-2和eNOS的表达。结果:去势各组血清T水平较正常对照组显著下降(P<0.05)。经3V、5V电压刺激后去势各组ICP/MAP值明显下降(P<0.05)。HO-2在正常和去势大鼠阴茎海绵体组织均有表达,去势4周组HO-2光密度分布曲线下面积(341.50±99.70)较正常组(876±443.36)和去势8周组(705.00±152.74)明显下降(P<0.05),去势8周与正常组之间无显著变化(P>0.05),去势12周没有检测到HO-2的表达。eNOS主要表达于阴茎海绵体血管内皮细胞,去势组eNOS(123.94±30.23)较正常组(421.21±125.12)差异有显著性(P<0.05)。T与eNOS和HO-2表达呈高度正相关(r=0.976、0.946,P均<0.05)。结论:雄激素可能通过影响大鼠阴茎海绵体HO-2、eNOS的表达参与阴茎勃起功能调控。     

高脂血症对大鼠阴茎海绵体中NOS及CO含量影响的研究

目的 探讨高脂血症对大鼠阴茎海绵体中一氧化氮合成酶(NOS)活性及一氧化碳(CO)浓度的影响及两者之间的关系.方法 将32只雄性wistar大鼠随机分为2组:高脂血症组和正常对照组,每组各16只大鼠.通过建立大鼠高脂血症模型,于实验开始后10d和20d,分别随机取各组1/2大鼠观察其勃起功能;用分光光度法分别测定海绵体匀浆中NOS活性和CO浓度.结果 在第10天及第20天,高脂血症组和正常对照组相比,大鼠阴茎海绵体内NOS活性、CO浓度及阴茎勃起次数差异均有统计学意义(P<0.05);而且第20天高脂血症组NOS活性、CO浓度及阴茎勃起次数,均明显低于第10天,两两比较差异均有统计学意义(P<0.05).结论 高脂血症大鼠阴茎海绵体中NOS及CO下降,这可能是高脂血症引起勃起功能障碍的发病机制之一.     

糖尿病大鼠阴茎海绵体组织nNOS神经变化的实验研究

目的 :研究糖尿病对大鼠阴茎海绵体组织nNOS神经纤维的影响。　方法 :34只SD雄性大鼠分为 6周组(17只 )和 8周组 (17只 ) ,其中每组各 11只腹腔注射链脲佐菌素制备糖尿病模型 ,其余各 6只注射柠檬酸缓冲液作为空白对照 ,分别在注射 6周和 8周后 ,观察大鼠阴茎勃起功能 ,并采用免疫组化SP法检测糖尿病大鼠阴茎组织nNOS神经纤维的数量。　结果 :2组糖尿病大鼠的阴茎勃起率分别为 37.5 %和 14 .3% ,差异有显著性 (P <0 .0 5 ) ,均明显低于对照组 (P <0 .0 1)。 2组糖尿病大鼠nNOS神经纤维的表达明显低于对照组 (P <0 .0 1)。 8周组中糖尿病大鼠阴茎的勃起功能和nNOS神经纤维的数量明显低于 6周组 ,分别为 (37.6 0± 6 .76 )条和 (2 8.0 0±5 .2 9)条 ,即随着病程的延长 ,勃起功能和nNOS神经纤维的表达下降 (P <0 .0 5 ) ,而对照组大鼠nNOS神经纤维的数量差异无显著性 [(83.0 0± 3.2 2 )vs(81.0 0± 3.6 1) ]。　结论 :糖尿病严重影响勃起功能和nNOS神经纤维的表达。糖尿病大鼠阴茎海绵体组织中nNOS神经纤维的数量明显减少 ,且与病程正相关 ,这可能是糖尿病性勃起功能障碍的发病机理之一。     

衰老对大鼠阴茎海绵体NOSⅠ的表达和NOS活性的影响

目的 :探讨衰老对大鼠阴茎海绵体一氧化氮合酶Ⅰ (NOSⅠ)mRNA、蛋白的表达和NOS活性的影响。　方法 :30只雄性SD大鼠按不同月龄分为成年组、老年组和衰老组 ,应用Western印迹、RT PCR方法分别检测不同年龄组阴茎海绵体NOSⅠ蛋白及mRNA的表达 ;用紫外分光光度计测定不同年龄组阴茎海绵体NOS的活性。　结果 :成年组NOSⅠ 蛋白的表达量最高 ,老年组和衰老组显著降低 ,分别为成年组的 75 .6 %和 6 1.2 % ;NOSⅠmRNA的表达与蛋白表达的变化一致 ;老年组NOS活性与成年组差异无显著性 (P >0 .0 5 ) ,衰老组NOS活性明显降低 ,是成年组的70 .4 % ,并且差异非常显著 (P <0 .0 1)。　结论 :衰老引起NOSⅠ 蛋白及mRNA的表达降低和NOS活性的显著降低 ,可能是老年性阴茎勃起功能障碍的主要机制之一。     

自发性高血压大鼠阴茎海绵体组织nNOS变化的实验研究

目的：研究高血压对大鼠阴茎海绵体组织nNOS神经纤维的影响。方法：自发性高血压大鼠(SHR)和同系WKY鼠各12只，都随机分为4周观察组(6只)和12周观察组(6只)。第4周和第12周末时，观察阴茎勃起功能，并检测阴茎组织nNOS神经纤维数目。结果：4周组和12周组中，SHR和WKY鼠在阴茎勃起次数和阴茎组织nNOS神经纤维数目上，都有显著差异(P＜0．01)。SHR4周组和SHR12周组，在阴茎组织nNOS神经纤维数目上，差异也有显著性(P＜0．05)，阴茎勃起次数和勃起率差异无显著性(P＞0．05)，但有减少的趋势。结论：高血压使阴茎组织中nNOS神经纤维数目减少，这可能是高血压引起勃起功能障碍的发病机理之一。     

糖尿病大鼠盆神经节nNOS表达和阴茎海绵体NOS活性的实验研究

阴茎勃起功能障碍（ED）是糖尿病（DM）常见的并发症之一，国外报道DM性ED发病率为50％～75％，其发病机制尚不清楚。勃起是一种神经控制的血流动力学变化过程，盆神经节控制进入阴茎的血流。本研究通过建立DM大鼠模型，检测盆神经节神经元型一氧化氮合酶（nNOS）的表达和海绵体NOS的活性，以进一步探讨DM性ED的发病机制。     

血红素加氧酶2和CO在去势大鼠阴茎海绵体中的表达

目的:检测去势大鼠阴茎海绵体中血红素加氧酶2(HO-2)/CO的表达,初步探讨勃起功能障碍(ED)的发病机制。方法:雄性SD大鼠72只均分为对照组、假手术组、去势组和去势锌原卟啉(Zn PP,HO阻断剂)组,检测基础条件和阿扑吗啡(APO)刺激后的海绵体内压(ICP)和勃起率;激光共聚焦显微镜检测大鼠勃起不同时期阴茎海绵体组织中HO-2蛋白的表达,分光光度计测定CO在大鼠勃起不同时期的含量。结果:基础条件和APO刺激后ICP和勃起率,去势组[(11.68±0.69)mm Hg,(54.81±3.86)mm Hg,33.3%]和去势Zn PP组[(11.20±0.71)mm Hg,(41.17±5.41)mm Hg,22.2%],与对照组[(22.83±2.66)mm Hg,(66.92±7.77)mm Hg,100%]和假手术组[(23.35±2.22)mm Hg,(70.43±7.22)mm Hg,100%]比较显著下降(P均0.01),且APO刺激后去势Zn PP组ICP较去势组明显降低(P0.01)。APO刺激后,勃起前和勃起中阴茎海绵体HO-2蛋白表达,去势组(445.4±23.7,847.4±35.0)和去势Zn PP组(390.1±29.7,526.0±52.5)较对照组(512.7±57.4,1 145.2±89.8)和假手术组(583.7±8.0,1 016.3±79.8)显著下降(P0.05或P0.01),且勃起中去势Zn PP组HO-2蛋白表达较去势组明显降低(P0.01);勃起后各组之间的HO-2蛋白表达变化差异无显著性。勃起前、中和后阴茎海绵体CO含量,去势组[(20.59±1.01)×10-7nmol/L,(32.53±1.26)×10-7nmol/L,(18.71±1.22)×10-7nmol/L]和去势Zn PP组[(12.52±1.05)×10-7nmol/L,(21.90±1.02)×10-7nmol/L,(16.56±0.55)×10-7nmol/L]较对照组[(26.76±1.41)×10-7nmol/L,(48.25±1.01)×10-7nmol/L,(27.10±1.58)×10-7nmol/L]和假手术组[(25.41±2.09)×10-7nmol/L,(47.90±1.22)×10-7nmol/L,(25.67±1.20)×10-7nmol/L]显著下降(P0.05或P0.01),且勃起中去势Zn PP组CO含量较去势组明显下降(P0.01)。结论:HO-2和CO表达下降与去势大鼠ED的发生有关。     

Relaxation effects of adrenomedullin in isolated rabbit corpus cavernosum smooth muscle

OBJECTIVES: To clarify the pharmacological effects of adrenomedullin, a potent vasodilator and hypotensive peptide isolated from human phaeochromocytoma cells, on corpus cavernosal smooth muscle in vitro, as the intracavernosal injection of adrenomedullin induces penile erection in the anaesthetized cat. MATERIALS AND METHODS: The effects of adrenomedullin were investigated in isolated muscle strips from New Zealand rabbit corpus cavernosum smooth muscle pre-contracted with phenylephrine alone, in the presence of indomethacin (cyclooxygenase inhibitor), Nomega-nitro l-arginine methyl ester (L-NAME, a nitric oxide synthase inhibitor), and K+-channel blockers. RESULTS: Adrenomedullin caused relaxation of isolated pre-contracted rabbit corpus cavernosum strips in a concentration-dependent manner. The response of corpus cavernosum was unaffected L-NAME, indomethacin and K+-channel blockers. CONCLUSION: The relaxation exerted by adrenomedullin in rabbit corporal tissue may arise from the effect of the drug on its specific receptors and/or calcitonin gene-related peptide-1 receptors. The relaxant effect of adrenomedullin might lead to novel clinical applications for erectile dysfunction.     

Application of correlation techniques in the analysis of corpus cavernosum electromyographic signals

Aim： To establish an objective, easy-to-use and comprehensive method to analyze corpus cavernosum electromyo- graphic signals （CC-potentials）. Methods： CC-potentials were recorded during flaccidity in 23 young healthy volunteers, with surface electrodes placed on the penile shaft bilaterally. Based on the correlation function of Matlab software, an application program for the analysis of CC-potentials was developed. Individual CC-potentials and their autocorrelation function were evaluated, yielding parameters amplitude （A）, duration （D）, and dominant frequency （DF）. The crosscorrelation function of both longitudinal and bilateral pairs of adjacent electrodes was calculated to assess the similar- ity and mutual delay of CC-potentials recorded simultaneously from different parts of the CC. The parameters derived were squared maximum cross-correlation coefficient （Rmax） and delay （τ）. Based on the absolute value of τ and the corresponding inter-electrode distance, propagation velocity （PV） was calculated. Results. The values of the parameters were determined automatically. No significant difference related to the locations of the electrodes for parameters A, D, and DF was detected. The cross-correlation showed that both longitudinal and bilateral CC-potential pairs had highly similar waveforms （the absolute values of Rmax were 0.80 ± 0.05 and 0.87 ± 0.06, respectively）. PV of longitudinal pairs was estimated as 6.15 ± 3.98 cm/s. Conclusion： The application program for correlation analysis of CC-potentials is a comprehensive and versatile method to analyze corpus cavernosum electromyographic recordings. Its objectiveness makes multi-center application possible.     

Alterations in nNOS-containing nerve fibers in corpus cavernosum of spontaneous hypertension rats

Objective: To investigate the alterations in nNOS containing nerve fibers in corpus cavernosum of spontaneous hypertension rats (SHR). Methods: Twelve male SHR and 12 male WKY rats, both aged 6 weeks, were separately divided into 4- and 12-week observation groups at random. At the end of the observation period, the erectile function was assessed and the number of cavernosal nNOS containing nerve fibers determined. Results: Significant differences existed in the erection frequency and the number of nNOS containing nerve fibers between the SHR rats and the WKY controls (P< 0.01); there was also a significant difference in the numbers of nNOS containing nerve fibers between the SHR 4- and 12-week observation groups (P<0.05). Conclusion: The erectile function and the number of nNOS containing nerve fibers were significantly reduced in SHR rats. The decrease in nNOS containing nerve fibers may be one of the mechanisms underlying erectile dysfunction in hypertensive rats.     

Three-dimensional mapping and comparative analysis of the distal human corpus cavernosum and the inflatable penile prosthesis

The intricate anatomy of the corpus cavernosum in both the flaccid and tumescent state has not been fully elucidated. We report our experience using a three-dimensional (3D) scanner to reconstruct cadaveric casts and compare them with 3D images of two prototypes of penile prosthesis. Two different models of the Titan Coloplast inflatable penile prosthesis were analyzed using a 3D scanner. The first was the standard model and the second was a newer model with a rounder silicone tip. Two cadaveric phalluses were harvested using Smooth-Cast 300Q polyurethane molding. The molds were excised and scanned along side the penile prosthesis. 3D scans were completed and analyzed using Leios Mesh software, and GOM Inspect software. The 3D scans demonstrated the mean human corporal radii 2 mm from the distal tip to be 36.51 mm (36.01–37.0 mm), which is an obtuse angle. The standard Titan penile prosthesis spherical radius at the same level was 202.52 mm, while the new silicone tip prosthesis had a radius of 139.33 mm. 3D mapping further demonstrated the trajectory of the cavernosa appeared curvilinear and the distal ends appeared blunt. The use of cadaveric cavernosal molds in combination with the 3D scanner allowed us to accurately image the corpus cavernosum for the first time. Our findings suggest that anatomically accurate corporal tips appear to be relatively blunt and that the new Titan silicone tip penile prosthesis more closely resembles the human corporal tip.     

Comparative studies on intracellular calcium and nadh fluorescence of the rabbit corpus cavernosum

Erectile function (erection and detumescence) involves the complex interaction of direct neuronal stimulation of corporal smooth muscle, neurohumoral release of specific endothelial contractile and relaxant factors, and secondary modulation by a variety of putative neuropeptides and vasoactive modulators. Using surface spectrofluorometry, we have correlated spontaneous contractile activity and the contractile response to field and pharmacological agents with intracellular calcium and NADH metabolism. The results demonstrate that the corpus cavernosal tissue has very unusual properties. Spontaneous contractile activity is correlated with a phasic increase in intracellular calcium. However, spontaneous contractile activity is most often correlated with a bi-phasic effect on the ratio of NADH/NAD. At the start of the spontaneous contraction, there is a sharp phasic increase in NADH/NAD; peak contractile force occurs simultaneous with a phasic decrease in this ratio showing that at peak force generation, there is a decrease in the level of intracellular energy. Phenylephrine stimulation results in an increase in intracellular calcium in proportion to the increase in tension; however, phenylephrine stimulation at low concentrations results in a net increase in the NADH/NAD ratio whereas high concentrations of phenylephrine result in a net decrease in the NADH/NAD ratio. In general, field stimulation results in a decrease in tension at low frequencies, a biphasic response at midfrequencies, and a contraction at high frequencies. These contractile responses are directly related to alterations in the intracellular concentration of calcium. That is, a decrease in tension is preceded by a decrease in intracellular calcium while an increase in tension is preceded by an increase in intracellular free calcium. Field stimulation results in a rapid and phasic alteration in the NADH/NAD ratio; however, the NADH/NAD response can be either an increase, decrease, or biphasic response. There does not appear to be a consistent relationship between the contractile/relaxant response to field stimulation and altered NADH/NAD ratio. Finally, ATP, bethanechol, and nitroprusside induce a decrease in the basal tension of the corpus cavernosal strips which corresponds with a decrease in the NADH/NAD ratio. However, whereas nitroprusside relaxation is correlated with a decreased intracellular calcium level, both ATP and bethanechol stimulate an increase in intracellular free calcium. These studies indicate that the response of the corpus cavernosal tissue to both field stimulation and pharmacological agents is complex and may involve both direct and indirect actions of a variety of cellular mediators on the corporal smooth muscle. © 1994 Wiley-Liss, Inc.     

The neuronal and endothelium-dependent relaxing responses of human corpus cavernosum under physiological oxygen tension last longer than previously expected

BACKGROUND: Intracavernosal oxygen tension varies greatly in the process of erection. Blood extracted from the human penis demonstrates an increase from approximately 30 mmHg Po(2) in the flaccid state to 100 mmHg in the erect state of the penis. In the present study, using these levels as a guide, we investigate how the NO-dependent relaxation of human corpus cavernosum changed under physiological oxygen tensions ranging from approximately 30 to 100 mmHg. METHODS: Human penile tissue specimens were obtained at penile surgery with informed consent from the patients. The preparations were mounted in Krebs solution in an organ bath and the isometric tension was recorded. Krebs solutions of various oxygen tensions were prepared by bubbling 5% CO(2) in N(2) and O(2). The NO-dependent relaxation caused by electrical field stimulation (EFS) and acetylcholine (ACh) was studied, and the amplitude and duration of relaxation evaluated. RESULTS: The amplitude of relaxation induced by EFS was significantly decreased under physiological oxygen tension conditions (P < 0.01). The duration of the relaxant response induced by EFS and ACh was significantly prolonged in physiological oxygen tension conditions than in high oxygen tension (P < 0.01). However, there was no correlation between the duration of relaxation induced by EFS and each physiological oxygen tension level. The duration of relaxation induced by ACh was most prolonged at 60-69 mmHg oxygen tension. CONCLUSION: Physiologically, the effect of NO may last longer than was previously thought. In addition, it would seem that there is an optimal physiological oxygen tension for maximum ACh-induced relaxation.     

Effect of sodium nitropmsside on hemodynamics of corpus cavemosum in Chinese

Aim: To study the effect of sodium nitroprusside (SNP) on the hemodynamics of corpus cavemosum in Chinese men with erectile dysfunction (ED). Methods: In 68 ED patients receiving intracavemous injection (ICI) of SNP, the cavemous hemodynamics were studied by Doppler ultrasonography. Results: The peak flow velocity (PFV), the artery diameter (Ad), the mean velocity of arterial blood (MV) and the vein diameter (Vd) were significantly higher after ICI of SNP than before ICI, but the end diastolic velocity (EDV) did not change significantly. Conclusion: The increase in Vd after SNP suggests that the venous outflow is not invariably decreased during penile election.