Stereological and biochemical analysis of muscular and connective tissue components in the penile corpus cavernosum adjacent to the fibrous plaque of Peyronie's disease

SHH regulates penile morphology and smooth muscle through a mechanism involving BMP4 and GREM1

BACKGROUND

The cavernous nerve (CN) is frequently damaged in prostatectomy and diabetic patients with erectile dysfunction (ED), initiating changes in penile morphology including an acute and intense phase of apoptosis in penile smooth muscle and increased collagen, which alter penile architecture and make corpora cavernosa smooth muscle less able to relax in response to neurotransmitters, resulting in ED.

AIM

Sonic hedgehog (SHH) is a critical regulator of penile smooth muscle, and SHH treatment suppresses penile remodeling after CN injury through an unknown mechanism; we examine if part of the mechanism of how SHH preserves smooth muscle after CN injury involves bone morphogenetic protein 4 (BMP4) and gremlin1 (GREM1).

METHODS

Primary cultures of smooth muscle cells were established from prostatectomy, diabetic, hypertension and Peyronie's (control) (N = 18) patients. Cultures were characterized by ACTA2, CD31, P4HB, and nNOS immunohistochemical analysis. Patient smooth muscle cell growth was quantified in response to BMP4 and GREM1 treatment. Adult Sprague Dawley rats underwent 1 of 3 surgeries: (1) uninjured or CN-injured rats were treated with BMP4, GREM1, or mouse serum albumin (control) proteins via Affi-Gel beads (N = 16) or peptide amphiphile (PA) (N = 26) for 3 and 14 days, and trichrome stain was performed; (2) rats underwent sham (N = 3), CN injury (N = 9), or CN injury and SHH PA treatment for 1, 2, and 4 days (N = 9).

OUTCOMES

Western analysis for BMP4 and GREM1 was performed; (3) rats were treated with 5E1 SHH inhibitor (N = 6) or IgG (control; N = 6) for 2 and 4 days, and BMP4 and GREM1 localization was examined. Statistics were performed by analysis of variance with Scheffé's post hoc test.

RESULTS

BMP4 increased patient smooth muscle cell growth, and GREM1 decreased growth. In rats, BMP4 treatment via Affi-Gel beads and PA increased smooth muscle at 3 and 14 days of treatment. GREM1 treatment caused increased collagen and smooth muscle at 3 days, which switched to primarily collagen at 14 days. CN injury increased BMP4 and GREM1, while SHH PA altered Western band size, suggesting alternative cleavage and range of BMP4 and GREM1 signaling. SHH inhibition in rats increased BMP4 and GREM1 in fibroblasts.

CLINICAL IMPLICATIONS

Understanding how SHH PA preserves and regenerates penile morphology after CN injury will aid development of ED therapies.

STRENGTHS AND LIMITATIONS

SHH treatment alters BMP4 and GREM1 localization and range of signaling, which can affect penile morphology.

CONCLUSION

Part of the mechanism of how SHH regulates corpora cavernosa smooth muscle involves BMP4 and GREM1.

Pathway analysis of microarray data from corpora cavernosal tissue of patients with a prostatectomy or Peyronie disease in comparison with a cavernous nerve-injured rat model of erectile dysfunction

INTRODUCTION

Patients with a prostatectomy are at high risk of developing erectile dysfunction (ED) that is refractory to phosphodiesterase type 5 inhibitors. The cavernous nerve (CN) is frequently damaged during prostatectomy, causing loss of innervation to the penis. This initiates corpora cavernosal remodeling (apoptosis and fibrosis) and results in ED.

AIM

To aid in the development of novel ED therapies, the current aim was to obtain a global understanding of how signaling mechanisms alter in the corpora cavernosa with loss of CN innervation that results in ED.

METHODS

Microarray and pathway analysis were performed on the corpora cavernosal tissue of patients with a prostatectomy (n = 3) or Peyronie disease (control, n = 3). Results were compared with an analysis of a Sprague-Dawley rat CN injury model (n = 10). RNA was extracted by TRIzol, DNase treated, and purified by a Qiagen Mini Kit. Microarray was performed with the Human Gene 2.0 ST Array and the RU34 rat array. Differentially expressed genes were identified through several analytic tools (ShinyGO, Ingenuity, WebGestalt) and databases (GO, Reactome). A 2-fold change was used as the threshold for differential expression.

OUTCOMES

Pathways that were altered (up- or downregulated) in response to CN injury in the prostatectomy patients and a rat CN injury model were determined.

RESULTS

Microarray identified 197 differentially expressed protein-coding genes in the corpora cavernosa from the prostatectomy cohort, with 100 genes upregulated and 97 genes downregulated. Altered signaling pathways that were identified that affect tissue morphology included the following: neurologic disease, cell death and survival, tissue and cellular development, skeletal and muscle development and disorders, connective tissue development and function, tissue morphology, embryonic development, growth and proliferation, cell-to-cell signaling, and cell function and maintenance. These human pathways have high similarity to those observed in the CN-injured rat ED model.

CLINICAL IMPLICATIONS

Significant penile remodeling continues in patients long after the acute surgical injury to the CN takes place, offering the opportunity for clinical intervention to reverse penile remodeling and improve erectile function.

STRENGTHS AND LIMITATIONS

Understanding how signaling pathways change in response to CN injury and how these changes translate to altered morphology of the corpora cavernosa and ensuing ED is critical to identify strategic targets for therapy development.

CONCLUSION

Altered signaling in pathways that regulate tissue homeostasis, morphogenesis, and development was identified in penes of patients with a prostatectomy, and competitive forces of apoptosis and proliferation/regeneration were found to compete to establish dominance after CN injury. How these pathways interact to regulate penis tissue homeostasis is a complex process that requires further investigation.

Sonic Hedgehog Signaling in Primary Culture of Human Corpora Cavernosal Tissue From Prostatectomy, Diabetic, and Peyronie's Patients

BACKGROUND

Cavernous nerve (CN) injury causes penile remodeling, including smooth muscle apoptosis and increased collagen, which results in erectile dysfunction (ED), and prevention of this remodeling is critical for novel ED therapy development.

AIM

We developed 2 peptide amphiphile (PA) hydrogel delivery vehicles for Sonic hedgehog (SHH) protein to the penis and CN, which effectively suppress penile distrophic remodeling (apoptosis and fibrosis), in vivo in a rat CN injury model, and the aim of this study is to determine if SHH PA can be used to regenerate human corpora cavernosal smooth muscle deriving from multiple ED origins.

METHODS

Corpora cavernosal tissue was obtained from prostatectomy, diabetic, hypertension, cardiovascular disease and Peyronie's (control) patients (n = 21). Primary cultures (n = 21) were established, and corpora cavernosal cells were treated with SHH protein, MSA (control), 5E1 SHH inhibitor, and PBS (control). Growth was quantified by counting the number of cells at 3-4 days. Statistics were performed by ANOVA with Scheffe's post hoc test. Concentration of SHH protein for maximal growth was optimized, and a more active SHH protein examined.

OUTCOMES

Cultures were characterized by immunohistochemical analysis with ACTA2, CD31, nNOS and P4HB, and smooth muscle was quantified in comparison to DAPI.

RESULTS

Cultures established were >97% smooth muscle. SHH protein increased growth of smooth muscle cells from prostatectomy, diabetic, and Peyronie's patients in a similar manner (49%-51%), and SHH inhibition decreased growth (20%-33%). There was no difference in growth using 25 ug and 10 ug SHH protein, suggesting a threshold concentration of SHH protein above which smooth muscle growth is enhanced. A more active lipid modified SHH peptide further enhanced growth (15%), indicating a more robust growth response. SHH increased growth in smooth muscle cells from hypertension (37%) and cardiovascular disease (32%) patients. SHH protein increased growth under normal and high glucose conditions, suggesting that high glucose conditions that may be present in under controlled diabetic patients would not detract from SHH regenerative capacity.

CLINICAL IMPLICATIONS

SHH PA would be beneficial to enhance smooth muscle regeneration in patients with ED of multiple etiologies.

STRENGTHS AND LIMITATIONS

Understanding how human corpora cavernosal tissue responds to SHH treatment is critical for clinical translation of SHH PA to ED patients.

CONCLUSION

Corpora cavernosal smooth muscle from all ED patients responded to SHH treatment with increased growth. Stupp, SI. Sonic Hedgehog Signaling in Primary Culture of Human Corpora Cavernosal Tissue From Prostatectomy, Diabetic, and Peyronie's Patients. J Sex Med 2022;19:1228-1242.

Pathway Enrichment Analysis of Microarray Data Fom Human Penis of Diabetic and Peyronie's Patients, in Comparison with Diabetic Rat Erectile Dysfunction Models

BACKGROUND

Erectile dysfunction (ED) is a debilitating medical condition in which current treatments are minimally effective in diabetic patients due to neuropathy of the cavernous nerve, a peripheral nerve that innervates the penis. Loss of innervation causes apoptosis of penile smooth muscle, remodeling of corpora cavernosa (penile erectile tissue) morphology, and ED.

AIM

In this study, microarray and pathway analysis were used to obtain a global understanding of how signaling mechanisms are altered in diabetic patients and animal models as ED develops, in order to identify novel targets for disease management, and points of intervention for clinical therapy development.

METHODS AND OUTCOMES

Human corpora cavernosal tissue was obtained from diabetic (n = 4) and Peyronie's (control, n = 3) patients that were undergoing prosthesis implant to treat ED, and BB/WOR diabetic (n = 5) and resistant (n = 5) rats. RNA was extracted using TRIzol, DNase treated, and purified by Qiagen mini kit. Microarray was performed using the Human Gene 2.0 ST Array. (i) Alterations in patient and diabetic rat pathway signaling were examined using several analytical tools (ShinyGO, Metascape, WebGestalt, STRING) and databases, (ii) Strengths/weaknesses of the different pathway analysis tools were compared, and (iii) Comparison of human and rat (BB/WOR and Streptozotocin) pathway analysis was performed. Two technical replicates were performed. P value (FDR) < .15 was used as threshold for differential expression. FDR < 0.05 was considered significant.

RESULTS

Microarray identified 182 differentially expressed protein-coding genes. Pathway analysis revealed similar enrichments with different analytical tools. Down regulated pathways include development, tubular structure, sprouting, cell death, ischemia, angiogenesis, transcription, second messengers, and stem cell differentiation. ED patients, who have diabetes, incur significant loss of normal regulatory processes required for repair and replacement of injured corpora cavernosal tissue. Combined with loss of apoptotic regulatory mechanisms, this results in significant architectural remodeling of the corpora cavernosa, and loss of regenerative capacity in the penis.

CLINICAL TRANSLATION

This first report of microarray and pathway analysis in human corpora cavernosa, is critical for identification of novel pathways pertinent to ED and for validating animal models.

STRENGTHS AND LIMITATIONS

The analysis of tissue specific gene expression profiles provides a means of understanding drivers of disease and identifying novel pathways for clinical intervention.

CONCLUSION

Penis from diabetic ED patients lacks capacity for maintenance of corpora cavernosal architecture and regeneration, which are critical points for intervention for therapy development.

The effect of zinc sulfate on penile corpus spongiosum after hypospadias repair in rats: A stereological study

Hypospadias repair involves correcting urethra defects and improving the wound healing process. Zinc has been well accepted as an effective agent in wound healing. This study aimed to investigate the effect of zinc on corpus spongiosum after experimental hypospadias in rats. The animals were divided into three groups. The control group rats underwent general anesthesia, but did not receive any surgeries and treatments. The second and third groups underwent surgeries and respectively received Distilled Water (DW, 2 ml) and zinc sulfate solution (2 ml, containing 4 mg zinc sulfate) by gavages twice a day for 14 days. Stereological methods were used to quantify the corpus spongiosum tissue. The volumes of corpus spongiosum, spongy tissue, urethral lumens, urethral epithelium, and collagen bundles and the number of fibroblasts were respectively amplified by 28%, 40%, 36%, 48%, 40%, and 29% in the surgery + zinc sulfate group in comparison to the surgery + DW group (p < 0.02). It can be concluded that consumption of 4 mg/day zinc sulfate for 14 days could improve the healing of hypospadias through increasing the population of fibroblasts, producing collagen bundles, and building a wider lumen and more epithelized urethra.

Comparison of the effects of pentoxifylline, simvastatin, tamoxifen, and losartan on cavernous bodies after penile fracture in rats: a stereological study

Penile fracture (PF) is described as a rupture and fibrosis of the cavernous bodies. This study aimed to collect quantitative data on the impacts of pentoxifylline, simvastatin, tamoxifen, and losartan on cavernous body structure after PF. The rats were divided into six groups. The control group received anesthesia and incision without actual PF. The other groups (second to sixth) underwent PF induction in addition to administration of distilled water, pentoxifylline (200 mg/kg/day), simvastatin (40 mg/kg/day), tamoxifen (10 mg/kg/day), and losartan (20 mg/kg/day) for 8 weeks. The volumes of cavernous bodies, collagen bundles, and vessels and number of fibroblasts were increased significantly in the PF group in comparison to the control rats (p < 0.01), indicating a fibrotic process. Moreover, the mean volume of the cavernous bodies decreased in the groups with PF that received pentoxifylline, simvastatin, tamoxifen, or losartan when compared with the PF group. However, the volumes of the collagen bundles and vessels as well as the population of fibroblasts remained at the control level or even lower in PF plus pentoxifylline, simvastatin, tamoxifen, and losartan groups. This indicated the anti-fibrotic effects of the four drugs. It can be concluded that pentoxifylline, simvastatin, tamoxifen, and losartan could reduce fibrosis activities by minimizing the formation of collagen bundles and vessels as well as decreasing the population of fibroblasts 8 weeks after PF. Yet, losartan brought about a better outcome compared with the other chemicals.

The comparison of the effect of phenylephrine and epinephrine on penile spongy tissue in rats after experimental hypospadias surgery: a quantitative stereological study

Background

Many factors including vasoconstrictor agents can interfere with wound healing process. This study aimed to compare the histopathological outcome of injection of two sympathomimetic drugs used during urologic surgery, including phenylephrine and epinephrine, on the structure of spongy tissue and urethra in a rat model of experimental hypospadias repair using stereological methods.

Methods

Male rats were allocated into three groups. The first group underwent surgery without using any agents. The second and third groups underwent surgery with diluted phenylephrine (1:5000) and diluted epinephrine (1:100000) injection in the urethral plate before operation, respectively. Quantitative histological evaluation of all penises was performed after 3 weeks.

Results

The results indicated no significant differences among the three groups regarding the vessels and urethral lumen and epithelium. However, the volumes of the spongy tissue and collagen bundles and the number of fibroblasts were significantly higher (35–55%) in surgery + phenylephrine and surgery + epinephrine groups in comparison to the surgery group (p < 0.05), with no preferences.

Conclusions

Hypospadias repair using phenylephrine and epinephrine injection showed no adverse effects. Furthermore, they might lead to better postoperative structural outcomes without any preferences. However, further experimental and human studies are required to draw a firm conclusion.

Stereological Comparison of Imbibed Fibrinogen Gauze versus Simple Gauze in External Packing of Grade IV Liver Injury in Rats

Objective

To evaluate the effect of imbibed fibrinogen gauze on survival, bleeding and healing in liver trauma.

Methods

This animal experimental study was conducted on 20 adult male Sprague-Dawley rats; with a mean weight of 300±50 gram; divided into two groups. Grade IV injury was induced to the subjects' liver. Then, the bleeding site was packed with simple gauze in the control group, and imbibed fibrinogen gauze in the experimental group. All animals were re-evaluated for liver hemostasis 48 hours after the initial injury. Bleeding in the intra peritoneal cavity was measured using Tuberculosis Syringe in the first and second operations. Subjects were followed-up for 14 days. Eventually, the rats were sacrificed and their livers were sent to a lab for stereological assessment. Statistical comparisons were performed via Mann-Whitney U-test using SPSS. P-Values less than 0.05 were considered to be statistically significant.

Results

Half of the rats in the control group died, while all the rats in the imbibed fibrinogen gauze group survived after two weeks (p= 0.032). Bleeding in the imbibed fibrinogen gauze was significantly less than control group, 48 hours' post-surgery (p<0.001). According to the stereological results, granulation tissue in the imbibed fibrinogen gauze group were more than the control group (P= 0.032). Also, fibrosis in the imbibed fibrinogen gauze group were more than the control group (P= 0.014).

Conclusion

Our study indicated that imbibed fibrinogen gauze can potentially control liver bleeding and improve survival through increasing granulation tissue and fibrosis in injured liver.

Understanding the cellular basis and pathophysiology of Peyronie's disease to optimize treatment for erectile dysfunction

Erectile dysfunction (ED) is a common condition that significantly impacts a man’s physical and psychological well-being. ED is often associated with Peyronie’s disease (PD), which is an abnormal curvature of the penis. Delayed treatment of or surgical invention for PD often results in ED and therefore unsatisfied patients. The pathophysiology of PD is incompletely understood, but has been studied extensively and based on our current understanding of PD physiology, many medical treatment options have been proposed. In this paper, we will review what is known about the pathophysiology of PD and the medical treatment options that have been trialed as a result. More investigations in regards to the basic science of PD need to be carried out in order to elucidate the exact mechanisms of the fibrosis, and propose new, more successful treatment options which should be implemented prior to the onset of ED.

Single vs. double layer suturing method repair of the urethral plate in the rabbit model of hypospadias

INTRODUCTION

There are different methods of urethroplasty in hypospadias. The present study aimed to compare the repair of the urethral plate by single vs. double layer suturing.

MATERIAL AND METHODS

Fifteen male rabbits were assigned to the control, single layer, and double layer urethral plate suturing groups (n = 5). Experimental hypospadias was induced in the second and third groups and the urethral plates were sutured. After two weeks, the penis was dissected out and underwent histopathological processing. Stereological studies were applied to obtain quantitative histological data regarding the structure of the urethra and the related part of the corpus spongiosum.

RESULTS

Volume density of the urethral epithelium (the fraction of unit volume of the urethra occupied by its epithelium) was higher in the single layer suturing group when compared to the double layer or control groups (p <0.01). Additionally, the volume density of the urethral lumen (the fraction of the corpus spongiosum that is occupied by the urethral lumen) in the single versus the double layer suturing groups was respectively 2.4 and 2 folds higher than that in the control group (p <0.01). Besides, the volume density of the lumen was significantly higher in the single layer suturing when compared to the double layer suturing group (p <0.01). However, no significant difference was observed among the study groups regarding the volume density of the collagen and vessels in the incised site of the penis which implied that the fraction of the urethra and surrounding corpus spongiosum was occupied by collagen and vessels.

CONCLUSIONS

Urethral plate repair by the single layer suturing method could be accompanied by higher epithelialization and wider lumen in the rabbit model of hypospadias.

Modifications of erectile tissue components in the penis during the fetal period

BACKGROUND

The penile erectile tissue has a complex microscopic anatomy with important functions in the mechanism of penile erection. The knowledge of such structures is necessary for understanding the normal physiology of the adult penis. Therefore, it is important to know the changes of these penile structures during fetal development. This study aims to analyze the development of the main components of the erectile tissue, such as collagen, smooth muscle fibers and elastic system fibers, in human fetuses.

METHODOLOGY/PRINCIPAL FINDINGS

We studied the penises of 56 human fetuses aged 13 to 36 weeks post-conception (WPC). We used histochemical and immunohistochemical staining, as well as morphometric techniques to analyze the collagen, smooth muscle fibers and elastic system fibers in the corpus cavernosum and in the corpus spongiosum. These elements were identified and quantified as percentage by using the Image J software (NIH, Bethesda, USA). From 13 to 36 WPC, in the corpus cavernosum, the amount of collagen, smooth muscle fibers and elastic system fibers varied from 19.88% to 36.60%, from 4.39% to 29.76% and from 1.91% to 8.92%, respectively. In the corpus spongiosum, the amount of collagen, smooth muscle fibers and elastic system fibers varied from 34.65% to 45.89%, from 0.60% to 11.90% and from 3.22% to 11.93%, respectively.

CONCLUSIONS

We found strong correlation between the elements analyzed with fetal age, both in corpus cavernosum and corpus spongiosum. The growth rate of these elements was more intense during the second trimester (13 to 24 WPC) of gestation, both in corpus cavernosum and in corpus spongiosum. There is greater proportional amount of collagen in the corpus spongiosum than in corpus cavernosum during all fetal period. In the corpus spongiosum, there is about four times more collagen than smooth muscle fibers and elastic system fibers, during all fetal period studied.

The pathophysiology of Peyronie's disease

OBJECTIVE

To review the contemporary knowledge of the pathophysiology of Peyronie's disease (PD).

METHODS

Medline was searched for papers published in English from 2000 to March 2013, using the keywords 'Peyronie's disease' and 'pathophysiology'.

RESULTS

More than 300 relevant articles were identified for the purpose of this review. Unfortunately only a few studies had a high level of evidence, and the remaining studies were not controlled in their design. Many theories have been proposed to explain the cause of PD, but the true pathogenesis of PD remains an enigma. Identifying particular growth factors and the specific genes responsible for the induction of PD have been the ultimate goal of research over the past several decades. This would provide the means to devise a possible gene therapy for this devastating condition. We discuss present controversies and new discoveries related to the pathophysiology of this condition.

CONCLUSION

PD is one of the most puzzling diseases in urology. The pathogenesis remains uncertain and there is still controversy about the best management. The pathogenesis of PD has been explored in animal models, cell cultures and clinical trials, but the results have led to further questions. New research on the aetiology and pathogenesis of PD is needed, and which will hopefully improve the understanding and management for patients with this frustrating disease.

Pentoxifylline attenuates transforming growth factor-beta1-stimulated elastogenesis in human tunica albuginea-derived fibroblasts part 2: Interference in a TGF-beta1/Smad-dependent mechanism and downregulation of AAT1

INTRODUCTION

Transforming growth factor-beta1 (TGF-beta1) contributes to the pathogenesis of Peyronie's disease (PD). Pentoxifylline (PTX) antagonizes the effects of TGF-beta1 and has been utilized in our clinic for the management of PD although the mechanisms of action are not entirely clear.

AIM

We studied cell-signaling pathways through which TGF-beta1 and PTX mediate collagen metabolism, elastin expression, and elastogenesis in tunica albuginea-derived fibroblasts (TADFs).

METHODS

TADFs from men with and without PD were cultured and treated with TGF-beta1 and PTX as monotherapy at differing concentrations and time points. Combination treatment (TGF-beta1 followed by PTX and vice versa) was also investigated.

MAIN OUTCOME MEASURES

Reverse-transcription polymerase chain reaction and Western blotting were utilized to assess differences in elastin metabolism and cellular signaling between groups. Alpha-1 antitrypin (AAT1) expression was assayed.

RESULTS

At doses greater than 0.1 ng/Ml, TGF-beta1 increased messenger ribonucleic acid (mRNA) and protein expression of elastin in a time-dependent fashion in TADF. PTX did not interfere with TGF-beta1 mediated upregulation of elastin mRNA and protein in TADF. However, pretreatment of TADF with PTX was associated with decreased expression of AAT1, decreased activity of the Smad1/5 pathway, and enhanced phosphorylation of the inhibitory Smad6.

CONCLUSION

Expression of elastin mRNA and protein is upregulated in TADF by TGF-beta1. PTX has no effect on elastin production but attenuates elastogenesis in TADF through an AAT1-related mechanism.

Pentoxifylline attenuates transforming growth factor-β1-stimulated collagen deposition and elastogenesis in human tunica albuginea-derived fibroblasts part 1: impact on extracellular matrix

INTRODUCTION

Transforming growth factor-β1 (TGF-β1) has been implicated in the pathogenesis of Peyronie's disease (PD) and also plays a role in collagen and elastin metabolism. Pentoxifylline (PTX) antagonizes the effects of TGF-β1 and has been utilized in our clinic for the management of PD.

AIM

We studied the effects of TGF-β1 and PTX on collagen metabolism and elastogenesis in tunica albuginea-derived fibroblasts (TADFs).

METHODS

TADFs from men with and without PD were cultured and treated with TGF-β1 and PTX as monotherapy at differing concentrations and time points. Combination treatment (TGF-β1 followed by PTX and vice versa) was also investigated.

MAIN OUTCOME MEASURES

Cell proliferation assay, enzyme-linked immunosorbent assay, and immunohistochemistry were utilized to assess the impact of TGF-β1 and PTX on TADF with respect to elastin and collagen I metabolism.

RESULTS

PTX inhibited fibroblast proliferation at doses of 100 µM. TGF-β1 stimulated elastogenesis and collagen I fiber deposition in TADF in a dose- and time-dependent fashion. Pretreatment with PTX dramatically attenuated TGF-β1-mediated elastogenesis and collagen fiber deposition in TADF from men with and without PD. Interestingly, production of collagen I was higher in untreated Peyronie's tunica (PT) cells relative to normal tunica (NT) cells; furthermore, PTX attenuated collagen production to levels similar to untreated control TADF in PT cells but not in NT cells, suggesting important intrinsic differences between PT and NT cells.

CONCLUSION

Both elastin and collagen are upregulated by TGF-β1 in TADF. This likely contributes to the PD phenotype. Pretreatment with PTX attenuates both collagen fiber deposition and elastogenesis in TADF exposed to TGF-β1; these effects suggest a useful role for PTX in the management of PD.

Structural analysis of the corpora cavernosa in patients with ischaemic priapism

STUDY TYPE

Therapy (case series).

LEVEL OF EVIDENCE

4.

OBJECTIVE

To evaluate, using quantitative and qualitative methods, the changes in the corpora cavernosa of patients with ischaemic priapism.

PATIENTS AND METHODS

We obtained samples of corpora cavernosa from seven patients with ischaemic priapism (mean age 38 years, range 28-44) who had a cavernous-glandular shunt. The control tissues were fragments of corpora cavernosa obtained from autopsies of seven age-matched men who died from causes unrelated to the urogenital tract. Histochemical and immunohistochemical techniques were used to assess and quantify the extracellular matrix and smooth muscle fibres. The volumetric density of smooth muscle, elastic fibres and collagen were determined in corpora cavernosa.

RESULTS

From the stereological analysis the mean (sd) values of volumetric density were: for collagen, control 34.76 (4.64), priapism 39.64 (2.91) (P = 0.002); elastic system fibres, controls 28.10 (2.85), priapism 36.10 (3.06) (P = 0.001); smooth muscle fibres, controls 43.37 (4.96), priapism 26.48 (5.00) (P < 0.001). There were significantly more fibrous elements of the connective tissue and significantly fewer smooth muscle fibres in the corpora cavernosa of patients with ischaemic priapism than in controls.

CONCLUSION

Ischaemic priapism is associated with early and significant changes in the components of the extracellular matrix and smooth muscle fibres of the corpora cavernosa. This could explain the frequent occurrence of erectile dysfunction found in patients with ischaemic priapism.