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.

Effect of tankyrase 1 on autophagy in the corpus cavernosum smooth muscle cells from ageing rats with erectile dysfunction and its potential mechanism

This study compared tankyrase 1 expression and autophagy quantity between erectile dysfunction （ED） and non-ED rats＇ corpus cavernosum smooth muscle cells （CSMCs）. This study aslo explored the effect and possible mechanism of tankyrase 1 on autophagy and cell proliferation in ageing ED rats＇ CSMCs. The intracavernous pres- sure and mean systemic arterial pressure were measured to investigate erectile function so that eight 24-month-old ED and eight 8-month-old male Wistar rats were choosed respectively. The rat CSMCs were isolated and cultured by enzyme digestion, in which tankyrase 1 expression and autophagy quantity were compared. Tankyrase 1 over-expression was induced with plasmid transfection by Lipofectamine^TM. The effect of tankyrase 1 overexpression on proliferation, autophagy and mTOR pathway in 24-month-old ED rats＇ CSMCs was measured by the cell growth curve in MTT assay, cell cycle analysis in flow cytometry （FCM）, key protein expression in Western blot, autophagy quantity in transmission electron microscopy, monodansylcadaverine staining and GFP-LC3 fluorescence. The primary CSMCs were confirmed by immunofluorescence, and the purity was 99.1% in FCM. Compared with that of 8-month-old rats, tankyrase 1 expression and autophagy quantity significantly decreased in 24-month-old ED rats＇ primary CSMCs （P 〈 0.01）. Tankyrase 1 overexpression significantly increased the growth rate （P 〈 0.05） and increased the S phase of cell cycle （P 〈 0.01）. The autophagosome quantity was remarkably increased （P 〈 0.01）, LC3-Ⅰ/Ⅱ and Beclin 1 were upregulated （P 〈 0.01 and P 〈 0.05）, and p-p70S6K （Thr389） was downregulated in 24-month-old ED rat CSMCs （P 〈 0.05）. In conclusion, Tankyrase 1 and autophagy decrease in the CSMCs from aging rats with ED, and tankyrase 1 may have a positive effect on proliferation by enhancing autophagy and regulating the mTOR signalling pathway.

Effects of plant extract neferine on cyclic adenosine monophosphate and cyclic guanosine monophosphate levels in rabbit corpus cavernosum in vitro

Aim： To further investigate the relaxation mechanism of neferine （NED, a bis-benzylisoquinoline alkaloid extracted （isolated） from the green seed embryo of Nelumbo nucifera Gaertn in China, on rabbit corpus cavernosum tissue in vitro. Methods： The effects of Nef on the concentrations of cyclic adenosine monophosphate （cAMP） and cyclic guanosine monophosphate （cGMP） in isolated and incubated rabbit corpus cavernosum tissue were recorded using ^125I radioimmunoassay. Results： The basal concentration of cAMP in corpus cavernosum tissue was 5.67 ± 0.97 pmol/mg. Nef increased the cAMP concentration in a dose-dependent manner （P 〈 0.05）, but this effect was not inhibited by an adenylate cyclase inhibitor （cis-N-[2-phenylcyclopentyl]azacyclotridec-1-en-2-amine, MDL-12, 330A） （P 〉 0.05）. The accumulation of cAMP induced by prostaglandin Et （PGEt, a stimulator of cAMP production） was also augmented by Nef in a dose-dependent manner （P 〈 0.05）. The basal concentration of cGMP in corpus cavernosum tissue is 0.44 ± 0.09 pmol/mg. Nef did not affect this concentration of cGMP, either in the presence or in the absence of a guanyl cyclase inhibitor （1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, ODQ） （P 〉 0.05）. Also, sodium nitroprusside （SNP, a stimulator of cGMP production）-induced cGMP production was not enhanced by Nef （P 〉 0.05）. Conclusion： Nef, with its relaxation mechanism, can enhance the concentration of cAMP in rabbit corpus cavernosum tissue, probably by inhibiting phosphodiesterase activity. （Asian JAndro12008 Mar; 10： 307-312）

Ex vivo relaxation effect of Cuscuta chinensis extract on rabbit corpus cavernosum

The effect of Cuscuta chinensis extract on the rabbit penile corpus cavernosum （PCC） was evaluated in the present study. Penises obtained from healthy male New Zealand white rabbits （2.5-3.0 kg） were precontracted with phenylephrine （Phe, 10 pmol I^-1） and then treated with various concentrations of Cuscuta chinensis extract （1, 2, 3, 4 and 5 mg ml^-1）. The change in penile tension was recorded, and cyclic nucleotides in the PCC were measured by radioimmunoassay （RIA）. The interaction between Cuscuta chinensis and sildenafil was also evaluated. The result indicated that the PCC relaxation induced by Cuscuta chinensis extract was concentration-dependent. Pre-treatment with an nitric oxide synthase （NOS） inhibitor （No〉 nitro-L-arginine-methyl ester, L-NAME）, a guanylyl cyclase inhibitor （1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-l-one, ODQ）, or a protein kinase A inhibitor （KT 5720） did not completely inhibit the relaxation. Incubation of penile cavernous tissue with the Cuscuta chinensis extract significantly increased cyclic guanosine monophosphate （cGMP） and cyclic adenosine monophosphate （cAMP） in the PCC. Moreover, the Cuscuta chinensis extract significantly enhanced sildenafil-induced PCC relaxation. In conclusion, the Cuscuta chinensis extract exerts a relaxing effect on penile cavernous tissue in part by activating the NO-cGMP pathway, and it may improve erectile dysfunction （ED）, which does not completely respond to sildenafil citrate.

Effect of sodium nitroprusside on hemodynamics of corpus cavernosum in Chinese

Aim: To study the effect of sodium nitroprusside (SNP) on the hemodynamics of corpus cavemosum in Chinese menwith erectile dysfunction (ED). Methods; In 68 ED patients receiving intracavemous injection (ICI) of SNP, thecavernous hemodynamics were studied by Doppler ultrasonography. Results: The peak flow velocity (PFV), theartery diameter (Ad), the mean velocity of arterial blood (MV) and the vein diameter (Vd) were significantly higherafter 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 erection.(Asian J Androl 2001 Dec; 3: 311 - 313)

Effects of Ligustrazine on the Contraction of Isolated Rabbit Corpus Cavernosum Strips

Summary： To investigate the role of ligustrazine on relaxation of the isolated rabbit corpus cavernosum tissue in vitro, the effects of ligustrazine on the corpus cavernosum were observed by using experimental method of smooth muscle strips. Concentration-responses to phenylephine （PE） and KCI were recorded. The results showed that ligustrazine concentration-dependently depressed the contraction response of smooth muscle strips induced by PE. The maximum percentage relaxation of cavernosal strips by ligustrazine was 74.1±6.2 % （compared with control： 21.9±5.6%, P〈0.01）. Ligustrazine concentration-dependently reduced the amplitude of the contraction induced by cumulative doses of PE or KCI, shifted the cumulative concentration response curves of PE and KCI to the right and depressed their maximal responses. It was concluded that ligustrazine could significantly relax the cavernosal muscle contraction induced by PE in vitro. The results suggested that ligustrazine inhibited calcium ion influx.

Testosterone replacement maintains smooth muscle content in the corpus cavernosum of orchiectomized rats

Objective:To evaluate the effects of testosterone(T)on the maintenance of corpus cavernosum(CC)structure and apoptosis.Methods:Animals were divided into three groups:sham operation group(n Z 8)underwent sham operation;Orchiectomized(Orchiec)t oily vehicle group(n Z 8)underwent bilateral orchiectomy and received a single dose of oily vehicle by intramuscular injection(i.m.)30 days after orchiectomy;and Orchiec t T group(n Z 8)underwent bilateral orchiectomy and received a single dose of T undecanoate 100 mg/kg i.m.30 days after the surgery.Animals were euthanized 60 days after the beginning of the experiment with an anesthetic overdose of ketamine and xylazine.Blood samples and penile tissue were collected on euthanasia.

Relaxation mechanisms of cavernosum tissue in vitro neferine on the rabbit corpus

Aim： To investigate the relaxation mechanisms of neferine （Nef） on the rabbit corpus cavemosum tissue in vitro. Methods： Strips of rabbit corpus cavemosum were mounted in organ chambers. The effects of Nef were examined on isolated muscle strips precontracted with phenylephrine （PE） alone, in the presence of NW-nitro-L-arginine （LNNA, a nitric oxide synthase inhibitor）, 1-H-[ 1,2,4]oxadiazolo[4,3-tx]quinoxalin- 1-one （ODQ, a guanylyl cyclase inhibitor）, indomethacin （cyclooxygenase inhibitor）, tetraethylammonium （Ca^2＋ -activated K^＋ channel blocker）, 4-aminopiridine （4-AP ,voltage dependent K^＋ channel blocker） and glibenclamide （ATP sensitive K^＋channel blocker）. The effects of Nef on KCl-induced contraction of isolated muscle strips were also investigated. The procedure of calcium absencecalcium addition was designed to observe the effect of Nef on two components of the contractile responses to PE based on the source of Ca^2＋ （extracellular vs. intracellular）. Results： Corpus cavemosum strips relaxed in response to Nef （10-9-10-4 mol/L） in a concentration-dependent manner with an IC50 of 4.60 × 10^-6 mol/L. However, they were not affected by LNNA, ODQ, indomethacin or K^＋-channel blockers. Nef （10^-6 mol/L, 10^-5 mol/L） concentration dependently reduced the maximal contraction response of isolated strips induced by KC1 to 79.3% ± 5.5% and 61.5% ±3.2%, respectively （P 〈 0.01）. In the calcium absence-calcium addition procedure, Nef 10.5 mol/L inhibited both intracellular calcium-dependent and extracellular calcium-dependent contraction induced by PE （2 × 10^5 mol/L） （P 〈 0.05）. The inhibition ratios were 26.2% ± 5.4% and 48.3% ±7.6%, respectively. Conclusion： The results of the present study suggest that Nef possesses a relaxant effect on rabbit corpus cavemosum tissues, which is attributable to the inhibition of extracellular Ca^2＋ influx and the inhibition of release of intracellular stored Ca^2＋, but not mediated by the release of nitric oxide, prostaglandins or by the activation of potassium channels.

Effect of Berberine on the mRNA Expression of Nitric Oxide Synthase(NOS) in Rat Corpus Cavernosum

Summary: In order to further investigate the mechanisms of action of berberine (Ber), we assessed the effects of Ber on the mRNA expression of nitric oxide synthases (NOS) in rat corpus cavernosum. After incubation with Ber for 1 or 3 h respectively, the levels of NOS mRNA were examined by reverse transcription polymerase chain reaction (RT-PCR). Our results showed that there were iNOS and eNOS mRNA expressions in rat corpus cavernosum. Ber enhanced eNOS mRNA expression in rat penis, but exhibited no effect on the expression of iNOS mRNA (P>0.05). The present study indicated that the relaxation of Ber involved the NO-cGMP signal thansduction pathway. The enhancing effect of Ber on eNOS mRNA expression might associated with its relaxation of corpus cavernosum.

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.

The relaxant effect of methanolic extract of yohimbe bark (<i>Pausinystalia yohimbe</i>) on rabbit corpus cavernosum smooth muscles

Background: Development and maintenance of penile erection requires the relaxation of corpus cavernosum smooth muscle (CCSM) cells and it is essentially mediated by nitric oxide (NO). Pausinystalia yohimbe bark is traditionally used for the treatment of erectile dysfunction (ED). Objectives and Methods: This study aimed to evaluate the effects of the methanolic extract of P. yohimbe bark (10 mg/ml) on isolated rabbit corpus cavernosum smooth muscle (CCSM). Results: Methanolic extract of P. yohimbe bark blocked contractions in CCSM induced by adrenergic agonists, through facilitating NO release from the endothelial cells. Conclusion: The obtained results revealed that, methanolic extract of P. yohimbe bark caused relaxation of CCSM that validates its traditional aphrodisiac property, thus it could be used to initiate and maintain erection in cases of erectile dysfunction.

A Rare Presentation of Partial Segmental Thrombosis of the Corpus Cavernosum Secondary to Sickle Cell Anemia

Background: Partial segmental thrombosis of the corpus cavernosum, known as partial priapism, is an uncommon urological condition which predominantly affects young men in which the proximal part of one corpus cavernosum is thrombosed. Many risk factors have been described in the literature, however, the exact etiology of penile thrombosis and its pathogenesis remains unclear. Several treatment options are available ranging from conservative medical treatment, surgical intervention, or simple follow-up observation without treatment. Aim: In this study, we describe a patient with sickle cell anemia who presented with pain and a perineal swelling that was eventually diagnosed as partial priapism utilizing MRI scan and was treated conservatively with a successful outcome. We then performed a literature search of similar cases highlighting incidence, risk factors and management of this rare presentation. Case Presentation: A 23-year-old male who is known with sickle cell anemia presented to casualty with a 1-day history of perineal pain of a sudden onset associated with perineal swelling and vomiting. Genitourinary exam findings confirmed the absence of classic priapism. Careful examination of his perineal area revealed the presence of a fixed, hard, and tender mass at the proximal part of the penis. It was not attached to the overlying skin and no enlarged pelvic lymph nodes were felt. Once stabilized, MRI of the pelvis was performed showing right intra-tunical corpus cavernosum features suggestive of hematoma in keeping with partial segmental thrombosis of the corpus cavernosum. Conservative treatment was initiated, and the patient was managed expectantly in which he improved gradually with eventual disappearance of the perineal mass. Conclusion: Partial segmental thrombosis of the corpus cavernosum is a rare urological condition. Pathogenesis and etiologies are poorly understood but risk factors have been advocated of which sickle cell anemia is one of them. MRI has a crucial role in the diagnosis under this condition. Conservative treatment appears to be a reliable initial therapeutic option.

Effects of buried penis on the structure and function of corpus cavernosum in a rat model

Background While the abnormal appearance of the concealed penis has been well recognized, the effect of buried penis on the structure and function of corpus cavernosum has not been well studied. To explore this issue, we established a rat model and evaluated the effect of buried penis on cavernosum weight, contents and ultrastructure of tissue, and nitric oxide synthase （NOS） activity. Methods Two hundred and ten rats were randomly divided into 3 equal cohorts for 2, 4 and 6 months study （groups A, B and C）. Each group was randomly divided into buried group （n=40）, control group （n=15）, and normal group （n=15）, respectively. Intra-purse-string suture of the root of the penis was used to establish the model. Macroscopic development was judged by measuring the weight of the corpus cavernosum. Masson＇s trichrome staining was performed for observing microstructure while a transmission electron microscope was used for observing ultrastructure. The NOS activity was detected by a NOS activity assay kit. Results Buried penis had no significant influence on the appearance and weight of the corpus cavernosum. Buried penis resulted in decreased smooth muscle content （P 〉0.05 in group A, and P 〈0.05 in groups B and C） and increased fibrous connective tissue content （P 〉0.05 in groups A and B, and P 〈0.05 in group C） compared with the normal and control groups. Ultrastructural abnormalities of corpus cavernosum were observed in the 6-month buried group. Moreover, there was decrease of NOS activity in groups B and C （P 〈0.05 in group B and P 〈0.01 in group C） when compared with the normal and control groups. Conclusion Buried penis affects the structure and function of corpus cavernosum in rats and the effect is positively correlated with the buried time, but there is no significant effect on the macroscopic development.

针灸关元穴治疗男性勃起功能障碍的作用机制研究

关元穴是目前泌尿生殖系统领域研究最为广泛的腧穴之一,也是在阴茎勃起功能障碍治疗中应用频率最高的穴位之一。针刺关元穴后,通过躯体-自主神经反射、细胞神经间突触样连接,传递生物化学信号,调控平滑肌细胞及血管内皮细胞,促使阴茎血管壁扩张、血流量增加和阴茎海绵体充血胀大;同时进一步沿着脊髓、脑水平传递神经冲动,提高中枢兴奋性。针灸通过调节下丘脑-垂体-性腺轴,促进促性腺激素释放、促黄体生成素及性激素的释放,调节性功能紊乱,还可以通过调控下丘脑-垂体-肾上腺轴来改善焦虑、抑郁情绪。此外,还可通过增强盆底肌力量、提高盆底肌肉本体感觉,改善勃起功能。然而,针刺关元穴兴奋男性阴茎勃起功能效应相关的分子生物学机制仍有待进一步完善。

地龙蛋白对糖尿病性勃起功能障碍大鼠阴茎海绵体平滑肌细胞表型转化及其勃起功能的影响

目的探讨地龙蛋白对糖尿病性勃起功能障碍(DMED)大鼠阴茎海绵体平滑肌细胞(CCSMC)表型转化及其勃起功能的影响。方法将60只勃起功能正常的雄性SD大鼠随机分为空白组、模型组、西地拉非组(5 mg·kg^(-1))及地龙蛋白低、中、高剂量组(45、90、180 mg·kg^(-1)),每组10只。采用腹腔注射链脲佐菌素(STZ,50 mg·kg^(-1))结合高脂饲料喂养建立糖尿病大鼠模型;8周后,颈部注射阿朴吗啡(APO,100μg·kg^(-1)),制备DMED大鼠模型。造模成功后,按剂量灌胃给药,每日1次,连续4周。测定各组大鼠造模前、造模第3天、给药4周后的血糖水平及体质量。采用多导生理记录仪测定大鼠阴茎海绵体内压(ICP)、颈动脉内压(MAP),计算ICP/MAP比值;免疫组织化学法检测阴茎海绵体中收缩型标志物α-平滑肌肌动蛋白(α-SMA)、平滑肌肌球蛋白重链(SMMHC)和合成型标志物Ⅰ型胶原蛋白(CollagenⅠ)、骨桥蛋白(OPN)表达情况;RT-PCR法检测阴茎海绵体中α-SMA、SMMHC、CollagenⅠm RNA表达水平;Western Blot法检测阴茎海绵体中α-SMA、肌间线蛋白(Desmin)、CollagenⅠ、OPN蛋白表达水平。结果与空白组比较,模型组大鼠在造模第3天和给药4周后的血糖值均显著升高(P<0.01),给药4周后的体质量显著降低(P<0.01);ICP及ICP/MAP比值显著降低(P<0.01);阴茎海绵体中α-SMA、SMMHC、Desmin蛋白表达水平显著降低(P<0.01),CollagenⅠ、OPN蛋白表达水平显著升高(P<0.01);阴茎海绵体中α-SMA、SMMHC m RNA表达水平显著降低(P<0.01),CollagenⅠm RNA表达水平显著升高(P<0.01)。与模型组比较,给药组大鼠的血糖值及体质量均无明显变化(P>0.05);ICP及ICP/MAP比值均显著升高(P<0.01);阴茎海绵体中α-SMA、SMMHC、Desmin蛋白表达水平显著升高(P<0.01),CollagenⅠ、OPN蛋白表达水平显著降低(P<0.01);阴茎海绵体中α-SMA、SMMHC m RNA表达水平显著升高(P<0.01),CollagenⅠmRNA表达水平显著降低(P<0.01)。结论地龙蛋白能够改善DMED大鼠勃起功能,其机制可能与通过抑制CCSMC由“收缩型”向“合成型(增殖型)”转化有关。

地龙蛋白对糖尿病性勃起功能障碍大鼠阴茎海绵体平滑肌细胞表型转化的影响

目的探讨地龙蛋白对糖尿病性勃起功能障碍(DMED)大鼠阴茎海绵体平滑肌细胞(CCSMC)表型转化的影响,以明确地龙蛋白改善DMED大鼠勃起功能的机制。方法于2021年7月选取60只SPF级雄性SD大鼠作为研究对象,随机选取50只腹腔注射链脲佐菌素(STZ),构建糖尿病(DM)大鼠模型,余下10只作为正常组。8周后大鼠颈部皮下注射阿朴吗啡(APO),并筛选出DMED大鼠。将DMED大鼠随机分为模型组、西地那非组及地龙蛋白低、中、高剂量组(45、90、180 mg/kg),各6只,并随机选取正常组6只作为空白组。给药4周后,检测大鼠血糖、体重、阴茎海绵体内压(ICP)和颈动脉内压(MAP)水平,计算ICP/MAP评估大鼠勃起功能。采用免疫组织化学法检测大鼠阴茎海绵体中收缩型标志物碱性调宁蛋白(Caiponin)、肌间线蛋白(Desmin)表达水平;采用实时荧光定量聚合酶链反应检测阴茎海绵体中Desmin、骨桥蛋白(OPN)mRNA表达水平;采用Western blotting法检测阴茎海绵体中Caiponin、平滑肌肌球蛋白重链(SMMHC)蛋白表达水平。结果与空白组比较,模型组大鼠体重、ICP/MAP显著下降,血糖显著升高(P<0.01);各给药组大鼠阴茎海绵体中Caiponin、Desmin表达显著下降(P<0.01);Desmin mRNA表达下降,OPN mRNA表达显著上升(P<0.01);Caiponin、SMMHC蛋白表达显著下降(P<0.01)。与模型组比较,西地那非组及地龙蛋白低、中、高剂量组大鼠ICP/MAP水平显著升高(P<0.01),但西地那非组及地龙蛋白低、中、高剂量组大鼠的体重及血糖水平比较,差异无统计学意义(P>0.05);各给药组大鼠阴茎海绵体中Caiponin、Desmin表达显著上升(P<0.01);Desmin mRNA表达显著上升,OPN mRNA表达显著下降(P<0.01);Caiponin、SMMHC蛋白表达显著上升(P<0.01)。结论地龙蛋白可通过上调阴茎海绵体组织中合成型(增殖型)标志蛋白或下调收缩型标志蛋白影响CCSMC转化,进而改善DMED大鼠的勃起功能。

Quantitative assessment of the aging corpus cavernosum by shear wave elastography

We wanted to determine whether shear wave elastography(SwE)could be used to evaluate the aging degree of the corpus cavernosum(CC)and to identify the histological basis of changes in SWE measurements during the aging process.We performed a crosssectional study enrolling healthy participants of different ages.We measured the Young's modulus(YM)of the penile CCs by SWE and assessed erectile function using the International Index of Erectile Function-5(IIEF-5).Histological investigation was performed in surgically resected penile specimens from a separate group of patients to examine the smooth muscle and collagen content of the CCs.Furthermore,we measured the YM,erectile function,smooth muscle,and collagen content of the CCs in different age groups of rats.Finally,we enrolled 210 male volunteers in this study.The YM of the CC(CCYM)was positively correlated with age(r=0.949,P<0.01)and negatively correlated with erectile function(r=-0.843,P<0.01).Histological examinations showed that cCs had increased collagen content but decreased smooth muscle content with increased age.The same positive correlation between CcYM and age was also observed in the animal study.In addition,the animal study showed that older rats,with increased CcYM and decreased erectile function,had lower smooth muscle content and higher collagen content.SwE can noninvasively and quantitatively evaluate the aging degree of the Cc.Increased collagen content and decreased smooth muscle content might be the histological basis for the effect of aging on the CC and the increase in its YM.

Effects of aqueous leaf extract of Tridax procumbens on contractile activity of corpus cavernosum in N-nitro-L-arginine methyl ester-induced hypertensive male rats

Objective： This study investigated the effects of aqueous leaf extract of Tridax procumbens （ALETP） on con- tractile activity of corpus cavernosum in N-nitro-L-arginine methyl ester （L-NAME）-induced hypertensive male rats. Methods： Twenty normal, adult male rats （130-150 g） were divided into four groups of five rats each. Group I （control） was given normal saline （0.6 mL/kg） and group II was given L-NAME （40 mg/kg） for 6 weeks. Groups Ill and IV also received L-NAME （40 mg/kg） for 6 weeks but were further co-treated with 100 and 200 mg/kg of ALETP, respectively, from week 4 to week 6. All treatments were given orally. Strips of corpus cavernosum from each of the four groups were exposed to increasing concentrations of acetyl~ choline （ACh） and sodium nitroprusside （SNP） （10^-9-10^-5 tool/L） after contraction with phenylephrine （10^-7 mol/L） to test for a dose-response effect, Response to potassium and calcium was also measured after cumulatively adding potassium and calcium （10-50 mmol/L） to potassium- and calcium-free organ chamber. Isometric contractions were recorded through an Ugo Basile data capsule acquisition system. Results： Mean arterial blood pressure was significantly reduced in the ALETP co-treated group compared to the control and L-NAME-only groups （P 〈 0.05）. Cavernosa strips from ALETP co-treated rats exhibited significant inhibition of contraction in response to phenylephrine, potassium chloride, and calcium chlo- ride （P 〈 0.05）. Relaxation in response to Ach and SNP was also significantly impaired in cavernosa strips from the L-NAME-only treated group （P 〈 0.05）, while ALETP co-treated groups showed enhanced per- centage relaxation. Conclusion： ALETP treatment of L-NAME-induced hypertensive rats promotes a relaxant effect on isolated cavernosa strips. ALETP shows potential in correcting erectile dysfunction in hypertension.

淫羊藿苷对家兔阴茎海绵体cGMP浓度的效果

目的 观察淫羊藿苷对家兔阴茎海绵体组织中cGMP浓度的影响。方法 应用12 5I放射免疫法 ,测定不同浓度的淫羊藿苷对阴茎海绵体内PDE5酶底物cGMP浓度的影响 ,并以西地那非和罂粟碱作为阳性对照。结果 淫羊藿苷能提高阴茎海绵体内cGMP浓度 ,具有浓度依赖性 (P<0 0 0 1) ,其半数有效浓度 (EC50 )为 5 13μmol·L-1,而西地那非 0 31为 μmol·L-1,罂素碱为 3 15 μmol·L-1。

淫羊藿苷对家兔阴茎海绵体环核苷酸水平的影响

目的深入研究淫羊藿苷(icariin,ICA)的壮阳作用机制。方法采用125I放射免疫测定法,以西地那非(sil-denafil,Sild)为阳性对照,观察ICA对家兔阴茎海绵体平滑肌组织中cGMP和cAMP水平的影响。结果ICA能直接升高cGMP的含量,但对cAMP含量无显著影响。在cGMP激动剂硝普钠(SNP)存在下,ICA和Sild均能浓度依赖性地提高海绵体组织中cGMP浓度(P<0.01),促进cGMP生成的EC50分别为4.62和0.42μmol/L。同样的条件下,ICA和Sild对cAMP的浓度均无显著影响(P>0.05)。在cAMP激动剂前列腺素E1(PGE1)刺激下,ICA和Sild也能够提高海绵体组织中cAMP的浓度(P<0.01),表现出浓度依赖性,促进cAMP生成的EC50分别为2.16、0.98μmol/L。结论ICA的壮阳作用机制与影响NO-cGMP信号通路有关,主要通过提高阴茎海绵体平滑肌中cGMP的浓度,从而舒张海绵体,增强阴茎勃起功能。