1-磷酸鞘氨醇受体1-3在Ⅰ型糖尿病ED大鼠阴茎海绵体组织中的表达

目的探讨1-磷酸鞘氨醇受体1-3(S1PR1-3)在糖尿病性勃起功能障碍大鼠阴茎海绵体组织中的表达。方法 20只成年雄性SD大鼠随机分为正常对照组和糖尿病组,成功造模2个月后,测定两组大鼠阴茎海绵体内压/平均动脉压(Max ICP/MAP),采用Western blot分析S1PR1-3、eNOS、RhoA、ROCK1、ROCK2的表达。结果与对照组相比,糖尿病组大鼠勃起功能显著降低(P0.05);糖尿病组大鼠阴茎海绵体S1PR1、S1PR3、eNOS蛋白表达水平下降(P0.05),而S1PR2、RhoA、ROCK1、ROCK2的表达升高(P0.05)。结论Ⅰ型糖尿病可导致大鼠勃起功能障碍,可能与S1PR1、S1PR3表达下调,eNOS/NO/cGMP信号通路受抑制以及S1PR2受体表达升高,激活RhoA/Rho激酶信号通路有关。     

携带S1P3 siRNA慢病毒载体改善自发性高血压大鼠勃起功能

目的:探讨携带S1P3 siRNA慢病毒载体对自发性高血压大鼠(SHR)勃起功能的改善作用。方法:5只12周龄健康雄性WKY大鼠为A组,随机将12周龄健康雄性SHR大鼠分组(每组5只):B1组:携带S1P3 siRNA慢病毒转染的SHR;B2组:空慢病毒载体(GFP)转染的SHR;C组:SHR大鼠对照组。B1组阴茎海绵体中部注射20μl携带S1P3 siRNA慢病毒(2×10~8TU/ml),B2组注射GFP 20μl (2×10~8TU/ml),每侧10μl。1周后测各组大鼠ICPmax/MAP值,免疫组化、Western印迹、RT-qPCR检测S1P3、ROCK1、ROCK2、eNOS mRNA及蛋白在各组大鼠阴茎海绵体中的表达。结果:各组大鼠体重、血清T水平无明显差异。A、B1、B2、C组大鼠在0、3、5 V电压刺激下ICPmax/MAP分别为:0V:0.16±0.01、0.15±0.01、0.10±0.00、0.11±0.01,3 V:0.55±0.03、0.55±0.01、0.22±0.01、0.22±0.01,5 V:0.82±0.02、0.79±0.03、0.43±0.01、0.42±0.02,C、B2组ICPmax/MAP较A、B1组显著降低(P0.05)。免疫组化结果显示,S1P3、ROCK1、ROCK2在A、B1组大鼠阴茎海绵体组织中表达水平与B2、C组相比明显减少(P0.05),eNOS则明显增加(P0.05);Western印迹结果显示,与B2、C组相比,A、B1组大鼠阴茎海绵体组织中S1P3、ROCK1、ROCK2蛋白表达显著减低(P0.05),eNOS显著升高(P0.05);A、B1、B2、C组S1P3基因相对表达量分别为:0.72±0.04、0.71±0.07、1.00±0.06、1.00±0.10,ROCK1:0.99±0.05、1.08±0.16、1.85±0.44、2.02±0.38,ROCK2:1.00±0.03、1.08±0.16、2.16±0.78、2.46±0.69,eNOS:1.04±0.15、0.81±0.23、0.32±0.08、0.32±0.04,S1P3、ROCK1、ROCK2在A组和B1组中的表达水平与C组、B2组相比明显减少(P0.05),eNOS明显增加(P0.05)。结论:携带靶向S1P3 siRNA慢病毒载体抑制阴茎海绵体组织内S1P3基因的表达,并下调RhoA/Rho激酶信号通路,从而改善SHR大鼠勃起功能。     

应用Rho激酶抑制剂对大鼠阴茎勃起的作用

目的 :探讨将RhoA/Rho激酶抑制剂Y 2 76 32涂抹于阴茎白膜表面以及阴茎龟头皮肤表面有无促进阴茎勃起的作用及其对体循环的影响。　方法 :2 0只成年雄性SD大鼠 ,体重为 2 5 0～ 30 0g ,随机分为实验组和对照组。全身麻醉后颈动脉和海绵体插管连续监测平均动脉压 (MAP)和阴茎海绵体内压 (CCP)的变化。寻找盆腔星状神经节(MPG)并以系列电刺激诱发勃起。向海绵体白膜表面及阴茎龟头皮肤表面涂抹Y 2 76 32 ,观察用药前后阴茎勃起的改变及MAP的改变。　结果 :将Rho激酶抑制剂Y 2 76 32涂抹于大鼠阴茎白膜表面和阴茎龟头皮肤表面均可促进在无阴茎支配神经电刺激下发生勃起 (ICP/MAP明显升高 ) ,在系列电刺激MPG时用药后发生的勃起反应较用药前亦明显增强。表面用药后还发现大鼠体循环血压有不同程度的降低。　结论 :阴茎皮肤表面应用Rho激酶抑制剂是一种安全有效的ED治疗方法 ,其临床应用价值仍有待于进一步探索     

P-Erk1/2和P-Akt1在高血压大鼠阴茎海绵体中的表达

目的:了解磷酸化Erk1/2(P-Erk1/2)和磷酸化Akt1(P-Akt1)在自发性高血压大鼠(SHR)和正常血压大鼠阴茎海绵体中的表达及与勃起功能的关系。方法:健康成年雄性SPF级SHR与对照组WKY大鼠各8只,14周龄,体重250～300g。麻醉后颈动脉和海绵体内插管连续监测平均动脉压(MAP)和海绵体内压(ICP),利用电刺激海绵体神经,记录ICP/MAP比值变化;免疫组织化学及RT-PCR技术检测P-Erk1/2和P-Akt1在大鼠阴茎海绵体的表达。结果:3V和5V电刺激海绵体神经后SHR组ICP/MAP比值(0.26±0.06、0.28±0.04)均较WKY组(0.46±0.12、0.76±0.13)显著降低(P均<0.05),P-Erk1、P-Erk2mRNA和P-Erk1/2蛋白的相对表达量在SHR组(0.81±0.05、0.91±0.06、54.22±10.05)较WKY组(0.42±0.04、0.68±0.14、7.05±1.45)显著升高(P均<0.05);P-Akt1mRNA和P-Akt1蛋白的相对表达量在SHR组(0.90±0.05、11.17±2.21)与WKY组(0.92±0.06、10.91±1.86)无显著差异(P均>0.05)。结论:高血压性勃起功能障碍的发生与阴茎海绵体P-Erk1/2的过度表达有关,而与P-Akt1的表达水平无明显相关。     

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。     

1-磷酸鞘氨醇受体1-3(S1P1-3)在去势雄性大鼠阴茎海绵体组织中的表达

目的:探讨1-磷酸鞘氨醇受体1-3(S1P1-3)在去势雄性大鼠阴茎海绵体内的表达,及其与NOS/NO/c GMP、Rho A/Rho激酶等信号通路的关系。方法:18只8周龄健康雄性SD大鼠,随机分为去势组、对照组及去势后睾酮替代组(替代组)各6只,去势组和替代组大鼠切除双侧睾丸、附睾,替代组大鼠去势术后给予生理剂量丙酸睾酮3 mg/(kg·d)皮下注射4周,对照组为假手术组,去势组及对照组大鼠术后给予等量植物油皮下注射4周,12周龄时,测定各组大鼠阴茎海绵体内压/平均动脉压(ICPmax/MAP)、采用免疫组化和Western印迹分析S1P1-3、e NOS、P-e NOS、ROCK1、ROCK2在阴茎海绵体内的表达变化。结果:去势组大鼠血清睾酮水平[(0.41±0.04)nmol/L]显著低于对照组[(16.01±1.02)nmol/L]及替代组[(15.84±1.32)nmol/L](P0.01),而替代组与对照组睾酮水平无显著差异。去势组ICPmax/MAP比值在0 V、3 V和5 V电刺激盆神经节时(0.088±0.014、0.323±0.014、0.432±0.012)均显著低于对照组(0.155±0.011、0.711±0.010、0.819±0.024)及替代组(0.153±0.012、0.696±0.017、0.763±0.027)(P0.01),而对照组与替代组无显著差异。去势组S1P1、e NOS、P-e NOS的蛋白表达量[以目的蛋白占内参GAPDH的百分率表示:S1P1(49.99±3.39)%,e NOS(46.82±3.81)%,P-e NOS(45.42±4.35)%]显著低于对照组[S1P1(72.57±3.06)%,e NOS(89.76±3.98)%,P-e NOS(82.53±8.92)%]和替代组[S1P1(71.77±4.43)%,e NOS(87.19±4.23)%,P-e NOS(79.82±7.38)%](P0.01),去势组S1P2、S1P3、ROCK1、ROCK2蛋白表达量[以目的蛋白占内参GAPDH的百分率表示:S1P2(82.35±4.13)%,S1P3(61.03±5.14)%,ROCK1(74.50±4.02)%,ROCK2(69.83±5.75)%]显著高于对照组[S1P2(41.67±1.68)%,S1P3(31.66±2.67)%,ROCK1(35.69±5.56)%),ROCK2(39.85±7.17)%]和替代组[S1P2(42.80±3.87)%,S1P3(32.25±4.22)%,ROCK1(38.06±5.21)%,ROCK2(42.36±4.44)%](P0.01)。结论:雄激素缺乏导致大鼠ICPmax/MAP显著降低,可能与阴茎海绵体内S1P1表达下调、抑制e NOS/NO/c GMP信号通路,S1P2、S1P3表达升高、激活Rho A/Rho激酶信号通路有关。     

血红素氧合酶2在慢性肾衰大鼠阴茎海绵体中的表达

目的:检测血红素氧合酶2(HO-2)在慢性肾衰(CRF)大鼠阴茎海绵体中的变化,探讨HO-2在阴茎勃起过程中的作用及与睾酮的关系。方法:采用10周龄雄性SD大鼠行5/6肾切除术构建CRF模型成功后,测定对照组(CTL组,n=15)、CRF组(n=15)平均颈动脉压(MAP)及海绵体内压最大值(ICPmax)、血清睾酮,并检测阴茎海绵体中eNOS、nNOS、HO-2的表达。结果:CRF组在3V、5V电刺激海绵体神经后ICPmax/MAP(0.121±0.084,0.135±0.088)均显著低于对照组(0.263±0.147,0.244±0.089,P<0.01),CRF组血清睾酮浓度[(1.190±0.946)nmol/L]显著低于对照组[(7.800±5.001)nmol/L,P<0.01],CRF组海绵体中nNOS、eNOS表达低于对照组,CRF组海绵体中HO-2表达(0.510±0.397)显著低于对照组(2.672±1.720,P<0.01),海绵体中HO-2表达下降与血清睾酮下降存在相关性(r=0.902,P<0.01)。结论:CRF组大鼠阴茎海绵体中nNOS、eNOS、HO-2、血清睾酮水平降低等可能是CRF并发勃起功能障碍机制之一。     

胱硫醚-γ-裂解酶和胱硫醚-β-合成酶在高血压大鼠阴茎海绵体中的表达

目的:探讨高血压对大鼠阴茎海绵体组织胱硫醚-γ-裂解酶(CSE)和胱硫醚-β-合成酶(CBS)表达的影响及与大鼠勃起功能的关系。方法:健康雄性SPF级自发性高血压大鼠(SHR)与对照组WKY(Wistar-Kyoto)大鼠各10只,于12周龄时测定大鼠血清睾酮、阴茎海绵体内压/平均动脉压(ICP/MAP)、血浆和阴茎海绵体内源性H2S的含量,采用免疫组化和Western印迹分析CSE和CBS在阴茎海绵体内的表达。结果:SHR与WKY大鼠的血清睾酮值没有显著差别,SHR的ICP/MAP在0、3和5 V电刺激盆腔神经节(MPG)时均显著低于WKY组(n=10,P0.05)。SHR血浆H2S含量显著低于WKY大鼠[(10.49±1.35)μmol/Lvs(21.92±2.75)μmol/L,P0.05],SHR阴茎海绵体组织内源性H2S含量显著低于WKY大鼠[(52.60±3.44)nmol/mg prot vs(87.67±2.12)nmol/mg prot,P0.05],SHR阴茎海绵体组织内源性H2S生成率也较WKY大鼠显著降低[(1.14±0.07)nmol/(mg·min)vs(4.35±0.32)nmol/(mg·min),P0.05]。CSE及CBS主要表达在SHR和WKY大鼠阴茎海绵体平滑肌细胞和血管内皮细胞的胞质,SHR的CSE及CBS蛋白表达量均显著低于WKY大鼠(P0.05)。ICP/MAP与CSE和CBS表达呈高度正相关(r=0.955、0.977,P均0.05)。结论:高血压大鼠阴茎海绵体组织中CBS和CSE的表达下降,导致阴茎海绵体内H2S合成减少,可能是高血压引起勃起功能下降的机制之一。     

抑制平滑肌的张力收缩:一种治疗勃起功能障碍的新途径

阴茎海绵体血管的收缩及张力的维持是由钙敏感的RhoA/Rho激酶信号传导途径介导的。以Y 2 76 32抑制海绵体平滑肌细胞的Rho激酶信号系统可促进阴茎勃起 ,表现为海绵体内压 (ICP)明显升高 ,而平均动脉压 (MAP)变化不显著。为什么在血管收缩信号很强的情况下性刺激仍能引发阴茎勃起反应 ?我们设想体内一氧化氮 (NO)能直接抑制RhoA/Rho激酶途径的活性 ,减少血管张力 ,促使血管舒张 ,勃起发生 ,使用Y 2 76 32可以恢复性腺功能低下和高血压病动物ED模型的阴茎勃起功能 ,这表明抑制Rho激酶活性药物具有临床应用的前景。此外 ,我们的结果显示阴茎表面使用Rho激酶抑制剂可能为ED治疗的有效方法之一。     

RhoA/Rho激酶在阴茎勃起中的作用

阴茎海绵体血管的张力受血管收缩和舒张因子的调控。通常认为NO舒张阴茎小动脉和海绵体平滑肌在阴茎勃起中具有重要作用。最近研究发现,RhoA/Rho激酶参与收缩因子去甲肾上腺素(NE)和内皮素1(ET-1)介导的阴茎小动脉和海绵体平滑肌收缩过程,与NO介导的海绵体平滑肌舒张过程有相互作用,NO的勃起效应可能与阻断RhoA/Rho激酶介导的阴茎海绵体血管平滑肌收缩有关。RhoA/Rho激酶抑制剂在ED的治疗中有广阔的应用前景。     

Low androgen status inhibits erectile function by up-regulating the expression of P2X receptors in rat corpus cavernosum

The aim of our study was to investigate whether low androgen level inhibits the erectile function of rats by regulating the expression of P2X receptors. Thirty-six 8-week-old male SD rats were randomly divided into six groups: sham-operated groups (4w-sham, 8w-sham), castration groups (4w-cast, 8w-cast) and androgen replacement after castration groups (4w-cast + T, 8w-cast + T). The maximum intracavernous pressure/mean arterial pressure (ICPmax/MAP), the levels of serum testosterone (T) and nitric oxide (NO), and the expression of P2X1, P2X2, P2X3, eNOS, p-eNOS, ROCK1 and ROCK2 in the cavernous tissue of rats were determined. The serum T, ICPmax/MAP and NO levels in penile corpus cavernosum in the castration groups were significantly lower than those in other groups (p < .01). The protein expression of P2X1, P2X2, P2X3, ROCK1 and ROCK2 in the castration groups was significantly higher than those in other groups (p < .01). P-eNOS/eNOS of the castration groups were significantly lower than those of other groups (p < .01). The serum T level was negatively correlated with the expression of P2X1, P2X2 and P2X3 in the corpus cavernosum. Low androgen level inhibits erectile function by up-regulating the expression of P2X1, P2X2, P2X3 and RhoA/Rho-kinase resulting in reducing the ratio of p-eNOS/eNOS and the level of NO in corpus cavernosum of rats.     

Endothelial nitric oxide synthase keeps erection regulatory function balance in the penis

OBJECTIVES: We evaluated the regulatory influence of endothelial nitric oxide (NO) on the basal functional states of the NO and RhoA/Rho-kinase signaling pathways in the penis using endothelial NO synthase (eNOS) mutant mice and eNOS gene transfer technology. METHODS: Four groups of mice were used: wild type (WT), eNOS gene deleted (eNOS-/-), eNOS and neuronal NOS gene deleted (dNOS-/-), and eNOS-/- mutant mice transfected intracavernosally with eNOS. Cyclic guanosine monophosphate (cGMP) concentration, protein kinase G (PKG) activity, activated RhoA, and Rho-kinase activity were determined in penes of WT and both mutant mouse groups. Constitutive NOS and PKG activities, RhoA, Rho-kinase-alpha and -beta isoforms, and phosphorylated myosin light-chain phosphatase target subunit (p-MYPT-1) expressions and Rho-kinase activity were determined in penes of eNOS-/- mice after eNOS gene transfer. RESULTS: Compared with results in the WT penis, eNOS-/- and dNOS-/- mutant mouse penes had significant reductions in NOS activity, cGMP concentration, PKG activity, Rho-kinase activity, and p-MYPT-1 expression (p<0.05) with no significant changes in activated RhoA or in RhoA and Rho-kinase-alpha and -beta protein expressions. After eNOS gene transfer to penes of eNOS-/- mice, Rho-kinase-beta and p-MYPT-1 expressions and total Rho-kinase activity were significantly increased from baseline levels (p<0.05). CONCLUSIONS: These data suggest that endothelial NO has a role in the penis as a regulator of the basal signaling functions of the NO and RhoA/Rho-kinase erection mediatory pathways. These data offer new insight into the homeostasis of erection regulatory biology.     

法舒地尔对高血压大鼠勃起功能的影响

目的:探讨Rho激酶抑制剂法舒地尔对高血压大鼠勃起功能的影响及其机制。方法:12周龄雄性SD大鼠随机分成对照组(A组)、高血压组(B组)、法舒地尔治疗组(C组),建立高血压大鼠模型后,C组给予法舒地尔[30 mg/(kg.d)]腹腔注射,A组、B组给予等量生理盐水腹腔注射,术后10周测量大鼠阴茎海绵体内压/平均颈动脉压(ICPmax/MAP),Western印迹法测定ROCK1、ROCK2蛋白在阴茎海绵体的表达水平。结果:B组收缩压(mmHg)、ROCK1、ROCK2蛋白表达(190.39±5.07、0.048±0.002、0.143±0.011)较A组(124.81±4.01、0.036±0.001、0.101±0.011)显著增加(P<0.05),C组收缩压(mmHg)、ROCK1、ROCK2蛋白表达(182.03±4.32、0.044±0.001、0.126±0.007)较B组显著降低(P<0.05),B组ICPmax/MAP(36.82±5.47)较A组(59.99±5.69)显著降低(P<0.05),C组(51.1±5.63)较B组显著提高(P<0.05)。结论:法舒地尔可通过抑制RhoA/Rho激酶信号高表达及可能的降血压作用而改善高血压大鼠勃起功能。     

Atorvastatin but not elocalcitol increases sildenafil responsiveness in spontaneously hypertensive rats by regulating the RhoA/ROCK pathway

Spontaneously hypertensive rats (SHR) are characterized by impaired erectile function and overactivity of the procontractile RhoA/Rho-associated, coiled-coil-containing protein kinase (RhoA/ROCK) pathway, as compared with their normotensive counterpart, Wistar-Kyoto rats. By measuring the intracavernous pressure:mean arterial pressure (ICP:MAP) ratio after electrostimulation of the cavernous nerve, we confirmed these findings and showed that responsiveness to sildenafil (25 mg/kg by oral gavage) also is hampered in SHR. A 2-week treatment with atorvastatin (5 and 30 mg/kg) improved the sildenafil-induced ICP:MAP increase and normalized RhoA and ROCK2 overexpression in SHR corpora cavernosa (CC). Conversely, other genes, neuronal nitric oxide synthase (NOS), endothelial NOS, and phosphodiesterase 5, were unaffected. In human fetal smooth muscle cells derived from CC (hfPSMC), atorvastatin inhibited RhoA membrane translocation and ROCK activity, as well as RhoA-dependent biologic functions like cell migration and cell proliferation. Atorvastatin's effect on migration was rescued in a dose-dependent manner by geranylgeranyl pyrophosphate, suggesting the involvement of RhoA geranylgeranylation. In hfPSMC, atorvastatin decreased the expression of RhoA-dependent genes such as ROCK2, desmin, alpha-smooth muscle actin, SM22alpha, and myocardin. In contrast to atorvastatin, elocalcitol, a vitamin D analog that also interferes with RhoA activation in SHR bladder, was unable to restore penile responsiveness to sildenafil. In conclusion, atorvastatin, but not elocalcitol, ameliorates sildenafil-induced penile erections in SHR, likely by interfering with RhoA/ROCK signaling within the penis.     

携带ROCK2基因siRNA有效片段的慢病毒载体的筛选

目的:筛选能够显著抑制自发性高血压大鼠(SHR)阴茎海绵体平滑肌细胞内ROCK2基因表达的携带ROCK2基因siRNA的慢病毒载体。方法:设计并合成4个靶向ROCK2的siRNA片段,构建并包装成慢病毒载体。随机将5只SHR阴茎海绵体平滑肌细胞分为6组,每组每个样本3×104个细胞,每组5个样本,分别为:A组(未转染对照组)、B组(携带慢病毒转染组)、C~F组(分别携带靶向ROCK2基因siRNA 1~4号靶点的慢病毒转染组),以感染复(MOI)=80转染SHR阴茎海绵体平滑肌细胞,转染后48 h荧光显微镜下观察细胞GFP表达情况,并用RT-PCR检测各组被转染细胞ROCK2 mRNA的表达。结果:荧光显微镜下观察各组细胞转染效率均50%。与A组相比,B组ROCK2 mRNA的表达无明显改变(P﹥0.05);C、D、F组SHR阴茎海绵体平滑肌细胞ROCK2基因mRNA的表达较A组极显著下降(P0.01),抑制效率分别达到(43.91±8.19)%、(47.15±6.64)%、(25.7±6.03)%;E组SHR阴茎海绵体平滑肌细胞ROCK2基因mRNA的表达较A组显著下降(P0.05),抑制效率为(16.81±5.94)%。结论:本研究构建的4种携带ROCK2基因的siRNA慢病毒载体均能够显著抑制SHR阴茎海绵体平滑肌细胞内ROCK2基因的表达,其中有1种慢病毒载体抑制作用最强。     

Nitric oxide synthase gene transfer for erectile dysfunction in a rat model

OBJECTIVE: To determine whether over-expression of nitric oxide synthase (NOS) in the corpus cavernosum of the penis improves erectile function, as NO is an important transmitter for genitourinary tract function, mediating smooth muscle relaxation and being essential for penile erection. MATERIALS AND METHODS: The inducible form of the enzyme NOS (iNOS) was introduced into the corpus cavernosum of adult Sprague-Dawley rats (250-300 g) by injecting a solution of plasmid, adenovirus or adenovirus-transduced myoblast cells (adeno-myoblasts). Plasmid, adenovirus and adeno-myoblasts encoding the expression of the beta-galactosidase reporter gene were also injected into rats. RESULTS: Throughout the corpora cavernosum there was expression of beta-galactosidase after injecting each of the three solutions. Maximum staining was greatest for adeno-myoblast, then adenovirus and then plasmid. The mean (sd) basal intracavernosal pressure (ICP) of iNOS-treated animals (adenovirus and adeno-myoblast) increased to 55 (23) cmH2O, compared with naive animals with a basal ICP of 5 (6) cmH2O (P = 0.001). Stimulating the cavernosal nerve (15 Hz, 1.5 ms, 10-40 V, 1 min) resulted in a doubling of the ICP (adenovirus and adeno-myoblast) from the basal level of the iNOS-treated animals. Direct in situ measurement of NO showed the release of 1-1.3 micro mol/L in the adeno-myoblast penis. CONCLUSION: Myoblast-mediated gene therapy was more successful for delivering iNOS into the corpus cavernosum than direct adenovirus injection or plasmid transfection. Surprisingly, implanting muscle cells into the penis is not only feasible but also beneficial. Gene therapy for NOS may open new avenues of treatment for erectile dysfunction. Control of NOS expression would be necessary to prevent priapism.