Tissue anisotropy and collagenomics in porcine penile tunica albuginea: Implications for penile structure-function relationships and tissue engineering

The tunica albuginea (TA) of the penis is an elastic layer that serves a structural role in penile erection. Disorders affecting the TA cause pain, deformity, and erectile dysfunction. There is a substantial clinical need for engineered replacements of TA, but data are scarce on the material properties and biochemical composition of healthy TA. The objective of this study was to assess tissue organization, protein content, and mechanical properties of porcine TA to establish structure-function relationships and design criteria for tissue engineering efforts. TA was isolated from six pigs and subjected to histomorphometry, quantification of collagen content and pyridinoline crosslinks, bottom-up proteomics, and tensile mechanical testing. Collagen was 20 ± 2%/wet weight (WW) and 53 ± 4%/dry weight (DW). Pyridinoline content was 426 ±131 ng/mg WW, 1011 ± 190 ng/mg DW, and 45 ± 8 mmol/mol hydroxyproline. Bottom-up proteomics identified 14 proteins with an abundance of >0.1% of total protein. The most abundant collagen subtype was type I, representing 95.5 ± 1.5% of the total protein in the samples. Collagen types III, XII, and VI were quantified at 1.7 ± 1.0%, 0.8 ± 0.2%, and 0.4 ± 0.2%, respectively. Tensile testing revealed anisotropy: Young's modulus was significantly higher longitudinally than circumferentially (60 ± 18 MPa vs. 8 ± 5 MPa, p < 0.01), as was ultimate tensile strength (16 ± 4 MPa vs. 3 ± 3 MPa, p < 0.01). Taken together, the tissue mechanical and compositional data obtained in this study provide important benchmarks for the development of TA biomaterials. STATEMENT OF SIGNIFICANCE: The tunica albuginea of the penis serves an important structural role in physiologic penile erection. This tissue can become damaged by disease or trauma, leading to pain and deformity. Treatment options are limited. Little is known about the precise biochemical composition and biomechanical properties of healthy tunica albuginea. In this study, we characterize the tissue using proteomic analysis and tensile testing to establish design parameters for future tissue engineering efforts. To our knowledge, this is the first study to quantify tissue anisotropy and to use bottom-up proteomics to characterize the composition of penile tunica albuginea.

Rutin ameliorates nitrergic and endothelial dysfunction on vessels and corpora cavernosa of diabetic animals

Endothelial dysfunction is an early complication of diabetes and it is related to both micro- and macroangiopathies. In addition, >70% of diabetic patients develop autonomic neuropathies. Increased oxidative stress has a major role in the development of both nitrergic and endothelial dysfunction. The aim of this work is to evaluate whether rutin, a potent antioxidant, could ameliorate nitrergic and/or endothelial dysfunction in diabetic animals. Primary and secondary treatment protocols with rutin were investigated on rat aortic rings and the mesenteric arteriolar bed, and on rabbit aortic rings and corpora cavernosa (RbCC) from both euglycemic and alloxan-diabetic animals. Acetylcholine endothelium-dependent and sodium nitroprusside endothelium-independent relaxations were compared in tissues from euglycemic or diabetic animals. Electrical field stimulation (EFS)-induced relaxation was performed only in the RbCC. Endothelial-dependent relaxations were blunted by 40% in vessels and neuronal relaxation was blunted by 50% in RbCC taken from diabetic animals when compared to euglycemic animals. Pre-treatment with rutin restored both neuronal and endothelial dependent relaxations in diabetic animals towards the values achieved in control euglycemic tissues. Rutin was able to ameliorate both endothelial dysfunction and nitrergic neuropathy in animal experimental models. Rutin could be a lead compound in the primary or secondary preventive ancillary treatment of endothelial and nitrergic dysfunction in the course of diabetes.

[Congenital penile curvature: Guidelines from the Andrology and Sexual Medicine Committee of the French Association of Urology (CAMS-AFU)]

INTRODUCTION

Guidelines regarding congenital penile curvature (CPC) are lacking, and this pathology has not been the subject of French recommendations to date. The Andrology and Sexual Medicine Committee (CAMS) of the French Association of Urology (AFU) propose a series of clinical practice recommendations (CPR) by answering five clinical questions concerning the diagnosis and treatment of this pathology.

MATERIALS AND METHODS

After a bibliographic research between 2000 and 2021, followed by a critical reading according to the CRP method. These recommendations were written to answer five questions: (1) What are the different types of CPC? (2) What are the reasons for consultation? (3) What are the assessment methods for CPCs and their consequences? (4) What are the indications for CPCs treatment? (5) What are the corrective modalities for the treatment of CPC?

RESULTS

There are two main phenotypes: CPC type 4 (the most common) and chordee without hypospadias. The diagnosis of CPC is clinical and established through enquiry and clinical examination associated with photos of the erect penis. Support can be offered if the curvature is responsible for a disability and/or sexual dissatisfaction linked to a deformation making penetration difficult and/or in the event of significant psychological impact. Only surgical treatments have demonstrated their effectiveness. For type 4 CPCs, corporoplasty (excisional, incisional, or incisionless techniques) is the gold standard.

CONCLUSION

These recommendations provide support for the management of patients consulting with CPC.

Occult penile fracture: An atypical presentation

Penile fracture is a urological emergency. Most cases are under reported due to social stigma. It is caused by rupture of the tunica -albuginea of corpora cavernosa.

Here we present an atypical case of penile fracture, with normal physical examination findings. But characteristic history and ultrasonography, led us to penile exploration and timely repair. Delay in diagnosis and treatment could have led to complications.

Objective of our case report is to raise suspicion of fracture penis in patients with typical history, even without physical findings with normal appearing penis. This helps in early repair and prevent complications.

X-ray micro-computed tomography in the assessment of penile cavernous fibrosis in a rabbit castration model

BACKGROUND

Current assessment methods of penile cavernous fibrosis in animal models have limitations due to the inability to provide complex and volume analysis of fibrotic alterations.

OBJECTIVE

The aim was to evaluate micro-computed tomography (micro-CT) for assessment of cavernous fibrosis and compare it with histological, histochemical, immunohistochemical, and RT-PCR analysis.

MATERIALS AND METHODS

A controlled trial was performed involving 25 New Zealand male rabbits with induced testosterone deficiency by orchidectomy. Penile samples were obtained before and after 7, 14, 21, 84 days from orchidectomy. We consistently performed: a) gray value analysis of corpora cavernosa 3D models reconstructed after micro-CT; b) morphometry of smooth muscles/connective tissue ratio, collagen type I/III ratio, and area of TGF-beta-1 expression in corpora cavernosa; c) RT-PCR of TGF-beta-1 expression.

RESULTS

Micro-CT allowed visualization of penile structures at the resolution comparable to light microscopy. Gray values of corpora cavernosa decreased from 1673 (1512-1773) on the initial day to 1184 (1089-1232) on 21 day (p < 0,005); however, on 84 day, it increased to 1610 (1551-1768). At 21 and 84 days, there were observed a significant decrease in smooth muscle/connective tissue ratio and a significant increase in collagen type I/III ratio (p < 0,05). TGF-beta1 expression increased on 84 day according to immunohistochemistry (p < 0,005). RT-PCR was impossible to conduct due to the absence of RNA in obtained samples after micro-CT.

DISCUSSION AND CONCLUSIONS

Micro-CT provided 3D visualization of entire corpora cavernosa and assessment of radiodensity alterations by gray value analysis in fibrosis progression. We speculate that gray value changes at early and late fibrosis stages could be related to tissue reorganization. RT-PCR is impossible to conduct on tissue samples studied by micro-CT due to RNA destruction. We also suggest that micro-CT could negatively affect the immunohistochemical outcome, as a significant increase of TGF-beta-1 expression occurs later than histological fibrotic signs. This article is protected by copyright. All rights reserved.

Segmental partial thrombosis of the corpora cavernosa: Case report and diagnostic/therapeutic algorithm

Cavernous body thrombosis is a rare condition. The etiology and pathophysiology of this entity is still poorly understood and there is no clear diagnostic and treatment algorithm. The objective of this article is to publish a clinical case of a partial segmental thrombosis of the corpus cavernosum and present a flow chart for diagnosis and treatment based on the review of the published literature on this disease.

Priapism and cannabism: A case report and review of the literature

Priapism is classically defined as a partial or complete erection, abnormally prolonged in the absence of desire or sexual stimulation. Several classes of drugs as well as certain psychoactive substances (e.g. alcohol, cocaine, cannabis, etc.) are accused in the occurrence of priapism. In this article, we report a case of priapism in a 37-year-old adult admitted to the emergency department after cannabis use. The patient received emergency aspiration of blood by puncturing the corpora cavernosa, followed by intra-cavernous injection of ephedrine. The evolution has been good. This case relates a rare side effect resulting from the consumption of cannabis, which requires a rapid assessment and management to avoid complications.

Priapism secondary to tamsulosin: A case report

BACKGROUND

Tamsulosin is the most potent adrenergic alpha-1 antagonist used for treatment of benign prostatic hyperplasia (BPH). Priapism has been reported as a rare side effect through direct inhibition of the sympathetic input necessary for detumesence.

PRESENTATION OF CASE

We describe an otherwise healthy man with recurrent and then persistent unresolved priapism after the use of tamsulosin and concomitant use of ace inhibitor and beta blocker for hypertension. We then performed aspiration and intracavernosal irrigation of saline and vasoconstrictive agent.

DISCUSSION

Health-care professionals should inform all patients taking such medications about this rare but possible serious adverse effect. Tamsulosin is a useful medication for the management of Lower Urinary Tract Symptoms (LUTS) related to BPH and medical expulsion of distal ureteric calculi. However, its use may be associated on rare occasions with priapism, hence Health-care professionals should be aware in order to advice all patients taking such medications about this rare but serious adverse effect and to seek help as soon as possible.

CONCLUSION

With caution against the use of tamsulosin in hypertension treated patient, the possibility of the adverse effect can be more noticed and encourage practitioners to look for other alternatives that are safer and better for dealing with LUTS in the future and develop better treatment strategies.

Improvement of endothelial function in a murine model of mild cholesterol-induced atherosclerosis by mineralocorticoid antagonism

BACKGROUND AND AIMS

The renin-angiotensin-aldosterone-system (RAAS) plays a role in endothelial dysfunction and atherosclerosis. During treatment with RAAS-inhibitors, elevated aldosterone may sustain "aldosterone escape".

METHODS

We investigated the effects of treatment with the mineralocorticoid antagonist eplerenone (Ep) compared with ramipril (Rami) or the combination of both on oxidative stress, plaque formation and endothelial function, in atherosclerotic apolipoprotein E deficient mice (ApoE(-/-)-mice). ApoE(-/-)-mice were fed a cholesterol rich diet (21% fat, 19.5% casein, 1.25% cholesterol) for 8 weeks to produce mild atherosclerosis (i.e. plaque load 20-30%). ApoE(-/-)-mice (control), ApoE(-/-)-mice treated with Ep (25 mg/kg/day), Rami (2.5 mg/kg/day) and their combination were compared. Heart rate (HR) and blood pressure (BP) were measured using the tail-cuff-method. Endothelial function was measured in aortic rings and corpora cavernosal strips (CCs). Atherosclerotic plaque burden, collagen content, oxidative stress (Dihydroethidium (DHE) staining) and macrophages were determined.

RESULTS

Treatments had no effects on HR and slightly reduced BP in ApoE(-/-)-mice treated with the combination of eplerenone and ramipril. Endothelium-dependent relaxation of aortic rings and CCs with carbachol was significantly improved in animals treated with Ep, Rami or their combination (p = 0.05 - p = 0.001). DHE-stained penile and aortic sections revealed a significant reduction in superoxide production in all treated groups (p = 0.035 - p = 0.001). In parallel, aortic and penile collagen content in ApoE(-/-)-mice was significantly decreased (p = 0.035 - p < 0.001) in animals treated with Ep, Rami or their combination. In agreement, there was a trend towards a reduction of aortic plaque area by treatment with Ep (-9.0 ± 3.2%) and Rami (-11.9 ± 4%). Only the treatment with the combination induced a significant reduction of the atherosclerotic plaque burden (p = 0.045). Moreover, the treatment of ApoE(-/-)-mice with Ep, Rami and their combination significantly reduced the count macrophage count in atherosclerotic plaque lesions. Ep restored endothelial function by reduction of oxidative stress, atherosclerotic macrophage content, atherosclerotic lesion size and fibrosis to the same extent as treatment with Rami or the combination.

CONCLUSIONS

Mineralocorticoid antagonism provides vasculoprotective effects and should be clinically evaluated for vascular disease such as erectile dysfunction.

Role of ultraosonography in grading of penile fractures

INTRODUCTION

Penile fracture is an uncommon and less reported condition. Early diagnosis with corrective measures is the order of the day.

AIM

To perform ultrasonography of penis and to understand its role in making correct diagnosis of fractures. To know how it will help surgeon in its management and in adopting a grading system.

MATERIALS AND METHODS

Emergency evaluation of 15 cases of penile fractures by ultrasonography before surgery. Entire penis was scanned all along its length and circumference. Tunica albugenia was seen as white covering of both corpora cavernosa and break in its continuity is seen as wedge shape defect. Hematoma on either sides of tunica was well appreciated.

RESULTS

After ultrasonography all patients underwent emergency surgery, the defect in corpora was well appreciated. Repair of tunica albugenia was done which confirmed our findings.

CONCLUSION

Ultrasonography is the modality of choice for quick diagnosis, and no other radiological workup is required before surgery.

Effects of the essential oil of Croton zehntneri and its major components, anethole and estragole, on the rat corpora cavernosa

AIMS

The effects of the essential oil of Croton zehntneri (EOCz) and its major components anethole, estragole and methyl eugenol were evaluated in phenylephrine precontracted rat corpora cavernosa (RCC).

MAIN METHODS

RCC strips were mounted in 5 ml organ baths for isometric recordings of tension, precontracted with 10 μM phenylephrine and exposed to test drugs.

KEY FINDINGS

All major compounds relaxed RCC. The order of potency was estragole>anethole>methyl eugenol. The maximal relaxation to EOCz and methyl eugenol was 62.67% (IC50 of 1.67 μM) and 45.8% (IC50 of 1.7 μM), respectively. Estragole relaxed RCC with an IC50 of 0.6 μM (maximal relaxation-76.6%). The maximal relaxation to estragole was significantly reduced by L-NAME (43.46%-IC50 of 1.4 μM), ODQ (53.11%-IC50 of 0.83 μM) and indomethacin (24.41%-IC50 of 1.3 μM). On the other hand, anethole relaxed RCC by 66.73% (IC50 of 0.96 μM) and this relaxation was blunted by indomethacin (35.65%-IC50 of 1.6 μM). Both estragole and anethole increased the relaxation achieved upon electrical stimulation. Both compounds increased the levels of cAMP (estragole by 3-fold and anethole by 2-fold when compared to controls). Estragole also increased the levels of cGMP (0.5-fold).

SIGNIFICANCE

The higher potency of these compounds to relax corpora cavernosa smooth muscle may form the pharmacological basis for the use of such substances as leading compounds in the search of alternative treatments of erectile dysfunction.

The venous drainage of the corpora cavernosa in the human penis

OBJECTIVE

To study the drainage proportions from the corpora cavernosa in defrosted human cadavers, as the veins related to penile erection were recently depicted to comprise the deep dorsal vein (DDV), a pair of cavernous veins (CVs) and two pairs of para-arterial veins (PAVs), as opposed to a single DDV between Buck's fascia and the tunica albuginea of the human penis.

MATERIALS AND METHODS

With no formalin fixation, 10 defrosted male human cadavers were used for this study. After injecting a 10% solution of colloid, and with the intracavernous pressure (ICP) fixed at 90 mmHg, the perfusion rate was recorded before and after the DDV, CVs and PAVs were removed, respectively. Finally, measurements were again recorded after penile arterial ligation. Cavernosography was used if required.

RESULTS

The mean (range) perfusion rate for maintaining the ICP at 90 mmHg was 30.2 (15.5-90.8) mL/min, whereas the arterial perfusion rate was 2.8 (0.3-3.9) mL/min. The mean (range) drainage proportion of the corpora cavernosa was 60.5 (50.3-69.7)%, 11.9 (5.8-22.9)% and 11.4 (5.2-15.0)% via the DDV, CVs and PAVs, respectively. The remaining drainage proportion was 15.6 (14.1-18.1)%. This study shows the separate drainage contributions of the DDV, CVs and PAVs to the corpora cavernosa of the human penis.

CONCLUSION

We conclude that the venous drainage system of the corpora cavernosa is much more complex than the previous depictions of it, and the consequent focus on a single DDV. This also shows the independent role of each venous system.

Treatment of erectile dysfunction: new targets and strategies from recent research

In recent years, research on penile erection has increasingly been centered on the molecular mechanisms involved. Major progress has been made in the field and at present a whole number of neurotransmitters, chemical effectors, growth factors, second-messenger molecules, ions, intercellular proteins, and hormones have been characterized as components of the complex process of erection. This knowledge has led to the discovery of several new therapeutic targets and multiple medical approaches for the treatment of erectile dysfunction (ED). This review focuses on the progress made in this field within the last few years.

Primary diffuse large B-cell lymphoma of the corpora cavernosa presented as a perineal mass

Primary male genital lymphomas may appear rarely in testis, and exceptionally in the penis and prostate, but there is not previous evidence of a lymphoma arising from the corpora cavernosa. We report the first case in the literature of a primary diffuse cell B lymphoma of the corpora cavernosa presented with low urinary tract symptoms, perineal pain and palpable mass. Diagnosis was based on trucut biopsy, histopathological studies and computed tomographic images.

Penile abscess and necrotizing fasciitis secondary to neglected false penile fracture

Penile infection and abscess formation have been described in association with priapism, cavernosography, intracavernosal injection therapy, trauma and penile prosthesis. We report a case of penile abscess and necrotizing fasciitis of penile skin in a 37-year-old male, presented 3 weeks after neglected false penile fracture.

Reversion of penile fibrosis: Current information and a new horizon

Ageing has a detrimental effect on cavernous tissue and the tunica albuginea of the penis. Furthermore, atherosclerosis of the penile vessels that occurs with ageing causes a decrease in penile oxygen tension. A reduction in smooth muscle cells (SMCs) was shown in relation to diminution of oxygen tension. Chronic ischaemia is therefore not only associated with fibrosis but also with nitric oxide-cyclic guanosine monophosphate reduction. The sensitivity of the α-adrenoceptors on the SMCs increases with ageing. The decrease in penile elasticity and compliance are explained by the changes in the ratio of penile collagen that occur with ageing. Contradictory to the view that testosterone is only necessary for sexual desire, numerous recent studies showed that androgen deprivation produces penile tissue atrophy, alterations in dorsal nerve structure, alterations in endothelial morphology, reduction in trabecular SM content, increase in deposition of extracellular matrix and accumulation of fat-containing cells (adipocytes) in the subtunical region of corpus cavernosum. The aim of the current review is to shed some light on the underlying aetiology of corporal fibrosis especially ageing, cavernous nerve damage, androgen deprivation and tunical fibrosis. Ultimately I will address the proposed prevention of erectile dysfunction associated with penile fibrosis.